HONEYCOMB-122 Update reader registry to share similar APIs as writer

+ Extract common registry builder base code
(Reader registry is not flat, so there is not full control over ordering as with writers
but it is sufficient)
+ Split CompositeReader into CompositeReader, SubtreeReader and GenericReader
+ No need to build composite structure in ReaderFactories (registry does that internally)
+ Keep only ReaderCustomizer + ListReaderCustomizer, no root reader (same for writers)

Change-Id: Ic4e5bc96ad47a6cbcada4efcc2209db5c16d2a6c
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

36 files changed, 75 insertions, 290 deletions

diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/initializers/VppInitializer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/initializers/VppInitializer.java
index 8c90c5051..8db903d8a 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/initializers/VppInitializer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/initializers/VppInitializer.java
@@ -55,7 +55,6 @@ public class VppInitializer extends AbstractDataTreeConverter<VppState, Vpp> {
 
         VppBuilder vppBuilder = new VppBuilder();
         BridgeDomainsBuilder bdsBuilder = new BridgeDomainsBuilder();
-
         bdsBuilder.setBridgeDomain(Lists.transform(operationalData.getBridgeDomains().getBridgeDomain(), CONVERT_BD));
         vppBuilder.setBridgeDomains(bdsBuilder.build());
         return vppBuilder.build();
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/AclCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/AclCustomizer.java
index 4e681f60a..cb8eed233 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/AclCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/AclCustomizer.java
@@ -18,8 +18,7 @@ package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
@@ -27,9 +26,7 @@ import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.Acl;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.future.FutureJVpp;
@@ -37,9 +34,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Customizer for enabling/disabling ACLs on given interface
+ * Customizer for enabling/disabling ACLs on given interface.
  */
-public class AclCustomizer extends FutureJVppCustomizer implements ChildWriterCustomizer<Acl>, AclWriter {
+public class AclCustomizer extends FutureJVppCustomizer implements WriterCustomizer<Acl>, AclWriter {
 
     private static final Logger LOG = LoggerFactory.getLogger(AclCustomizer.class);
     private final NamingContext interfaceContext;
@@ -52,13 +49,6 @@ public class AclCustomizer extends FutureJVppCustomizer implements ChildWriterCu
         this.classifyTableContext = checkNotNull(classifyTableContext, "classifyTableContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<Acl> extract(@Nonnull final InstanceIdentifier<Acl> currentId,
-                                 @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getAcl());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<Acl> id, @Nonnull final Acl dataAfter,
                                        @Nonnull final WriteContext writeContext) throws WriteFailedException {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/EthernetCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/EthernetCustomizer.java
index dd3a85628..27081b1b2 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/EthernetCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/EthernetCustomizer.java
@@ -16,15 +16,12 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.v3po.util.AbstractInterfaceTypeCustomizer;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.iana._if.type.rev140508.EthernetCsmacd;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.Ethernet;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
@@ -43,13 +40,6 @@ public class EthernetCustomizer extends AbstractInterfaceTypeCustomizer<Ethernet
         return EthernetCsmacd.class;
     }
 
-    @Nonnull
-    @Override
-    public Optional<Ethernet> extract(@Nonnull final InstanceIdentifier<Ethernet> currentId,
-                                      @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getEthernet());
-    }
-
     @Override
     protected final void writeInterface(@Nonnull final InstanceIdentifier<Ethernet> id,
                                        @Nonnull final Ethernet dataAfter, @Nonnull final WriteContext writeContext) {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/InterfaceCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/InterfaceCustomizer.java
index de07bdcc1..ac57ab4da 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/InterfaceCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/InterfaceCustomizer.java
@@ -16,7 +16,6 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
@@ -24,13 +23,10 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import java.util.concurrent.CompletionStage;
 import javax.annotation.Nonnull;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.Interfaces;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.InterfaceKey;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.SwInterfaceSetFlags;
@@ -89,14 +85,6 @@ public class InterfaceCustomizer extends FutureJVppCustomizer implements ListWri
         // TODO Handle deletes
     }
 
-    @Nonnull
-    @Override
-    public Optional<List<Interface>> extract(@Nonnull final InstanceIdentifier<Interface> currentId,
-                                   @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((Interfaces) parentData).getInterface());
-    }
-
-
     private void setInterface(final InstanceIdentifier<Interface> id, final Interface swIf,
                               final WriteContext writeContext)
         throws VppBaseCallException, WriteTimeoutException {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/L2Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/L2Customizer.java
index dd40fbdd0..83b522b63 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/L2Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/L2Customizer.java
@@ -16,23 +16,20 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.L2;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class L2Customizer extends FutureJVppCustomizer implements ChildWriterCustomizer<L2> {
+public class L2Customizer extends FutureJVppCustomizer implements WriterCustomizer<L2> {
 
     private static final Logger LOG = LoggerFactory.getLogger(L2Customizer.class);
     private final NamingContext interfaceContext;
@@ -45,12 +42,6 @@ public class L2Customizer extends FutureJVppCustomizer implements ChildWriterCus
         this.icWriteUtils = new InterconnectionWriteUtils(vppApi, interfaceContext, bridgeDomainContext);
     }
 
-    @Nonnull
-    @Override
-    public Optional<L2> extract(@Nonnull final InstanceIdentifier<L2> currentId, @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getL2());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<L2> id, @Nonnull final L2 dataAfter,
                                        @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RewriteCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RewriteCustomizer.java
index 9fa57830a..54c6971a8 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RewriteCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RewriteCustomizer.java
@@ -18,9 +18,8 @@ package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;
 
-import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils;
@@ -36,11 +35,9 @@ import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527._802dot1q;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.L2;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.l2.Rewrite;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.l2.RewriteBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.tag.rewrite.PushTags;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.L2InterfaceVlanTagRewrite;
@@ -53,7 +50,7 @@ import org.slf4j.LoggerFactory;
  * Writer Customizer responsible for vlan tag rewrite.<br> Sends {@code l2_interface_vlan_tag_rewrite} message to
  * VPP.<br> Equivalent of invoking {@code vppctl set interface l2 tag-rewrite} command.
  */
-public class RewriteCustomizer extends FutureJVppCustomizer implements ChildWriterCustomizer<Rewrite> {
+public class RewriteCustomizer extends FutureJVppCustomizer implements WriterCustomizer<Rewrite> {
 
     private static final Logger LOG = LoggerFactory.getLogger(RewriteCustomizer.class);
     private final NamingContext interfaceContext;
@@ -64,13 +61,6 @@ public class RewriteCustomizer extends FutureJVppCustomizer implements ChildWrit
         this.interfaceContext = Preconditions.checkNotNull(interfaceContext, "interfaceContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<Rewrite> extract(@Nonnull final InstanceIdentifier<Rewrite> currentId,
-                                     @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((L2) parentData).getRewrite());
-    }
-
     @Override
     public void writeCurrentAttributes(final InstanceIdentifier<Rewrite> id, final Rewrite dataAfter,
                                        final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RoutingCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RoutingCustomizer.java
index 9d41afd0c..1e8102133 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RoutingCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/RoutingCustomizer.java
@@ -16,18 +16,17 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
+import java.util.concurrent.CompletionStage;
+import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.Routing;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.SwInterfaceSetTable;
@@ -36,10 +35,7 @@ import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.annotation.Nonnull;
-import java.util.concurrent.CompletionStage;
-
-public class RoutingCustomizer extends FutureJVppCustomizer implements ChildWriterCustomizer<Routing> {
+public class RoutingCustomizer extends FutureJVppCustomizer implements WriterCustomizer<Routing> {
 
     private static final Logger LOG = LoggerFactory.getLogger(RoutingCustomizer.class);
     private final NamingContext interfaceContext;
@@ -49,13 +45,6 @@ public class RoutingCustomizer extends FutureJVppCustomizer implements ChildWrit
         this.interfaceContext = interfaceContext;
     }
 
-    @Nonnull
-    @Override
-    public Optional<Routing> extract(@Nonnull final InstanceIdentifier<Routing> currentId,
-                                     @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getRouting());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<Routing> id,
                                        @Nonnull final Routing dataAfter, @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceAclCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceAclCustomizer.java
index 9cba9c724..eb433dc37 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceAclCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceAclCustomizer.java
@@ -19,7 +19,7 @@ package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils;
@@ -40,10 +40,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Customizer for enabling/disabling ACLs on given sub-interface
+ * Customizer for enabling/disabling ACLs on given sub-interface.
  */
 public class SubInterfaceAclCustomizer extends FutureJVppCustomizer
-    implements ChildWriterCustomizer<Acl>, AclWriter {
+    implements WriterCustomizer<Acl>, AclWriter {
 
     private static final Logger LOG = LoggerFactory.getLogger(SubInterfaceAclCustomizer.class);
     private final NamingContext interfaceContext;
@@ -56,13 +56,6 @@ public class SubInterfaceAclCustomizer extends FutureJVppCustomizer
         this.classifyTableContext = checkNotNull(classifyTableContext, "classifyTableContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<Acl> extract(@Nonnull final InstanceIdentifier<Acl> currentId,
-                                 @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((SubInterface) parentData).getAcl());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<Acl> id, @Nonnull final Acl dataAfter,
                                        @Nonnull final WriteContext writeContext) throws WriteFailedException {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceCustomizer.java
index 57676c85b..c4971867c 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceCustomizer.java
@@ -20,7 +20,6 @@ import static com.google.common.base.Preconditions.checkState;
 import static io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils.getSubInterfaceName;
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;
 
-import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
@@ -40,7 +39,6 @@ import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev1
 import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.dot1q.tag.or.any.Dot1qTag;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527._802dot1ad;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.SubInterfaces;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterface;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterfaceKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.MatchType;
@@ -48,7 +46,6 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.vlan.tagged.VlanTagged;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.Tags;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.tags.Tag;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.CreateSubif;
@@ -74,14 +71,6 @@ public class SubInterfaceCustomizer extends FutureJVppCustomizer
         this.interfaceContext = Preconditions.checkNotNull(interfaceContext, "interfaceContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<List<SubInterface>> extract(@Nonnull final InstanceIdentifier<SubInterface> currentId,
-                                                @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((SubInterfaces) parentData).getSubInterface());
-    }
-
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<SubInterface> id,
                                        @Nonnull final SubInterface dataAfter, @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceL2Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceL2Customizer.java
index 8ab3e2c12..567122d31 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceL2Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/SubInterfaceL2Customizer.java
@@ -16,8 +16,7 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils;
@@ -29,7 +28,6 @@ import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterface;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterfaceKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.L2;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
@@ -38,7 +36,7 @@ import org.slf4j.LoggerFactory;
 /**
  * Customizer for writing vlan sub interface l2 configuration
  */
-public class SubInterfaceL2Customizer extends FutureJVppCustomizer implements ChildWriterCustomizer<L2> {
+public class SubInterfaceL2Customizer extends FutureJVppCustomizer implements WriterCustomizer<L2> {
 
     private static final Logger LOG = LoggerFactory.getLogger(SubInterfaceL2Customizer.class);
     private final NamingContext interfaceContext;
@@ -51,12 +49,6 @@ public class SubInterfaceL2Customizer extends FutureJVppCustomizer implements Ch
         this.icWriterUtils = new InterconnectionWriteUtils(vppApi, interfaceContext, bridgeDomainContext);
     }
 
-    @Nonnull
-    @Override
-    public Optional<L2> extract(@Nonnull final InstanceIdentifier<L2> currentId, @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((SubInterface) parentData).getL2());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<L2> id, @Nonnull final L2 dataAfter,
                                        @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/TapCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/TapCustomizer.java
index d0e5179e2..6de3bc457 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/TapCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/TapCustomizer.java
@@ -16,29 +16,30 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.v3po.util.AbstractInterfaceTypeCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
+import java.util.concurrent.CompletionStage;
+import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.PhysAddress;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.Tap;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
-import org.openvpp.jvpp.dto.*;
+import org.openvpp.jvpp.dto.TapConnect;
+import org.openvpp.jvpp.dto.TapConnectReply;
+import org.openvpp.jvpp.dto.TapDelete;
+import org.openvpp.jvpp.dto.TapDeleteReply;
+import org.openvpp.jvpp.dto.TapModify;
+import org.openvpp.jvpp.dto.TapModifyReply;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.annotation.Nonnull;
-import java.util.concurrent.CompletionStage;
-
 public class TapCustomizer extends AbstractInterfaceTypeCustomizer<Tap> {
 
     private static final Logger LOG = LoggerFactory.getLogger(TapCustomizer.class);
@@ -49,13 +50,6 @@ public class TapCustomizer extends AbstractInterfaceTypeCustomizer<Tap> {
         this.interfaceContext = interfaceContext;
     }
 
-    @Nonnull
-    @Override
-    public Optional<Tap> extract(@Nonnull final InstanceIdentifier<Tap> currentId,
-                                   @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getTap());
-    }
-
     @Override
     protected Class<? extends InterfaceType> getExpectedInterfaceType() {
         return org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.Tap.class;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VhostUserCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VhostUserCustomizer.java
index 60df2cf37..d087f30f5 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VhostUserCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VhostUserCustomizer.java
@@ -16,7 +16,6 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
-import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import io.fd.honeycomb.v3po.translate.v3po.util.AbstractInterfaceTypeCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
@@ -24,22 +23,24 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
+import java.util.concurrent.CompletionStage;
+import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VhostUserRole;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.VhostUser;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
-import org.openvpp.jvpp.dto.*;
+import org.openvpp.jvpp.dto.CreateVhostUserIf;
+import org.openvpp.jvpp.dto.CreateVhostUserIfReply;
+import org.openvpp.jvpp.dto.DeleteVhostUserIf;
+import org.openvpp.jvpp.dto.DeleteVhostUserIfReply;
+import org.openvpp.jvpp.dto.ModifyVhostUserIf;
+import org.openvpp.jvpp.dto.ModifyVhostUserIfReply;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.annotation.Nonnull;
-import java.util.concurrent.CompletionStage;
-
 /**
  * Writer Customizer responsible for passing vhost user interface CRD operations to VPP
  */
@@ -53,13 +54,6 @@ public class VhostUserCustomizer extends AbstractInterfaceTypeCustomizer<VhostUs
         this.interfaceContext = Preconditions.checkNotNull(interfaceContext, "interfaceContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<VhostUser> extract(@Nonnull final InstanceIdentifier<VhostUser> currentId,
-                                       @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getVhostUser());
-    }
-
     @Override
     protected Class<? extends InterfaceType> getExpectedInterfaceType() {
         return org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VhostUser.class;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanCustomizer.java
index 382348012..82c572864 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanCustomizer.java
@@ -18,7 +18,6 @@ package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
 import static com.google.common.base.Preconditions.checkArgument;
 
-import com.google.common.base.Optional;
 import com.google.common.net.InetAddresses;
 import io.fd.honeycomb.v3po.translate.v3po.util.AbstractInterfaceTypeCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
@@ -32,10 +31,8 @@ import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VxlanTunnel;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.Vxlan;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.VxlanAddDelTunnel;
@@ -55,13 +52,6 @@ public class VxlanCustomizer extends AbstractInterfaceTypeCustomizer<Vxlan> {
         this.interfaceContext = interfaceContext;
     }
 
-    @Nonnull
-    @Override
-    public Optional<Vxlan> extract(@Nonnull final InstanceIdentifier<Vxlan> currentId,
-                                   @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getVxlan());
-    }
-
     @Override
     protected Class<? extends InterfaceType> getExpectedInterfaceType() {
         return VxlanTunnel.class;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanGpeCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanGpeCustomizer.java
index 9b7e4bdbd..ebe7bfeab 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanGpeCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/VxlanGpeCustomizer.java
@@ -18,7 +18,6 @@ package io.fd.honeycomb.v3po.translate.v3po.interfaces;
 
 import static com.google.common.base.Preconditions.checkArgument;
 
-import com.google.common.base.Optional;
 import com.google.common.net.InetAddresses;
 import io.fd.honeycomb.v3po.translate.v3po.util.AbstractInterfaceTypeCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
@@ -32,10 +31,8 @@ import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceAugmentation;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VxlanGpeTunnel;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces._interface.VxlanGpe;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.VxlanGpeAddDelTunnel;
@@ -44,7 +41,6 @@ import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-// TODO extract common code from all Interface type specific writer customizers into a superclass
 public class VxlanGpeCustomizer extends AbstractInterfaceTypeCustomizer<VxlanGpe> {
 
     private static final Logger LOG = LoggerFactory.getLogger(VxlanGpeCustomizer.class);
@@ -55,13 +51,6 @@ public class VxlanGpeCustomizer extends AbstractInterfaceTypeCustomizer<VxlanGpe
         this.interfaceContext = interfaceContext;
     }
 
-    @Nonnull
-    @Override
-    public Optional<VxlanGpe> extract(@Nonnull final InstanceIdentifier<VxlanGpe> currentId,
-                                   @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppInterfaceAugmentation) parentData).getVxlanGpe());
-    }
-
     @Override
     protected Class<? extends InterfaceType> getExpectedInterfaceType() {
         return VxlanGpeTunnel.class;
@@ -102,25 +91,25 @@ public class VxlanGpeCustomizer extends AbstractInterfaceTypeCustomizer<VxlanGpe
     }
 
     private void createVxlanGpeTunnel(final InstanceIdentifier<VxlanGpe> id, final String swIfName,
-                                      final VxlanGpe VxlanGpe, final WriteContext writeContext)
+                                      final VxlanGpe vxlanGpe, final WriteContext writeContext)
         throws VppBaseCallException, WriteTimeoutException {
-        final byte isIpv6 = (byte) (isIpv6(VxlanGpe) ? 1 : 0);
-        final InetAddress Local = InetAddresses.forString(getAddressString(VxlanGpe.getLocal()));
-        final InetAddress Remote = InetAddresses.forString(getAddressString(VxlanGpe.getRemote()));
+        final byte isIpv6 = (byte) (isIpv6(vxlanGpe) ? 1 : 0);
+        final InetAddress Local = InetAddresses.forString(getAddressString(vxlanGpe.getLocal()));
+        final InetAddress Remote = InetAddresses.forString(getAddressString(vxlanGpe.getRemote()));
 
-        int vni = VxlanGpe.getVni().getValue().intValue();
-        byte protocol = (byte) VxlanGpe.getNextProtocol().getIntValue();
-        int encapVrfId = VxlanGpe.getEncapVrfId().intValue();
-        int decapVrfId = VxlanGpe.getDecapVrfId().intValue();
+        int vni = vxlanGpe.getVni().getValue().intValue();
+        byte protocol = (byte) vxlanGpe.getNextProtocol().getIntValue();
+        int encapVrfId = vxlanGpe.getEncapVrfId().intValue();
+        int decapVrfId = vxlanGpe.getDecapVrfId().intValue();
 
-        LOG.debug("Setting VxlanGpe tunnel for interface: {}. VxlanGpe: {}", swIfName, VxlanGpe);
+        LOG.debug("Setting VxlanGpe tunnel for interface: {}. VxlanGpe: {}", swIfName, vxlanGpe);
         final CompletionStage<VxlanGpeAddDelTunnelReply> VxlanGpeAddDelTunnelReplyCompletionStage =
                 getFutureJVpp().vxlanGpeAddDelTunnel(getVxlanGpeTunnelRequest((byte) 1 /* is add */, Local.getAddress(),
                     Remote.getAddress(), vni, protocol, encapVrfId, decapVrfId, isIpv6));
 
         final VxlanGpeAddDelTunnelReply reply =
                 TranslateUtils.getReplyForWrite(VxlanGpeAddDelTunnelReplyCompletionStage.toCompletableFuture(), id);
-        LOG.debug("VxlanGpe tunnel set successfully for: {}, VxlanGpe: {}", swIfName, VxlanGpe);
+        LOG.debug("VxlanGpe tunnel set successfully for: {}, VxlanGpe: {}", swIfName, vxlanGpe);
         if(interfaceContext.containsName(reply.swIfIndex, writeContext.getMappingContext())) {
             final String formerName = interfaceContext.getName(reply.swIfIndex, writeContext.getMappingContext());
             LOG.debug("Removing updated mapping of a vxlan-gpe tunnel, id: {}, former name: {}, new name: {}",
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4AddressCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4AddressCustomizer.java
index a05bd8f08..26d05546b 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4AddressCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4AddressCustomizer.java
@@ -20,23 +20,19 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static io.fd.honeycomb.v3po.translate.v3po.interfaces.ip.Ipv4WriteUtils.addDelAddress;
 import static io.fd.honeycomb.v3po.translate.v3po.interfaces.ip.Ipv4WriteUtils.getSubnetMaskLength;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.Ipv4;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.Address;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.AddressKey;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.address.Subnet;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.address.subnet.Netmask;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.address.subnet.PrefixLength;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.DottedQuad;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.future.FutureJVpp;
@@ -75,11 +71,6 @@ public class Ipv4AddressCustomizer extends FutureJVppCustomizer implements ListW
         setAddress(false, id, dataBefore, writeContext);
     }
 
-    @Override
-    public Optional<List<Address>> extract(InstanceIdentifier<Address> currentId, DataObject parentData) {
-        return Optional.fromNullable((((Ipv4) parentData).getAddress()));
-    }
-
     private void setAddress(boolean add, final InstanceIdentifier<Address> id, final Address address,
                             final WriteContext writeContext) throws WriteFailedException {
 
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4Customizer.java
index cee64742b..7eb45b2e4 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4Customizer.java
@@ -16,23 +16,20 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces.ip;
 
-import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.Interface1;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.Ipv4;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class Ipv4Customizer extends FutureJVppCustomizer implements ChildWriterCustomizer<Ipv4> {
+public class Ipv4Customizer extends FutureJVppCustomizer implements WriterCustomizer<Ipv4> {
 
     private static final Logger LOG = LoggerFactory.getLogger(Ipv4Customizer.class);
     private final NamingContext interfaceContext;
@@ -42,14 +39,6 @@ public class Ipv4Customizer extends FutureJVppCustomizer implements ChildWriterC
         this.interfaceContext = interfaceContext;
     }
 
-    // TODO replace guava's Optionals with Java8
-    @Nonnull
-    @Override
-    public Optional<Ipv4> extract(@Nonnull final InstanceIdentifier<Ipv4> currentId,
-                                  @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((Interface1) parentData).getIpv4());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<Ipv4> id,
                                        @Nonnull final Ipv4 dataAfter, @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4NeighbourCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4NeighbourCustomizer.java
index 99267ddff..426d81fbc 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4NeighbourCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv4NeighbourCustomizer.java
@@ -20,7 +20,6 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.MappingContext;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
@@ -29,13 +28,11 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.Ipv4;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.Neighbor;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.ipv4.NeighborKey;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.IpNeighborAddDel;
@@ -116,12 +113,6 @@ public class Ipv4NeighbourCustomizer extends FutureJVppCustomizer
         }
     }
 
-    @Override
-    public Optional<List<Neighbor>> extract(@Nonnull InstanceIdentifier<Neighbor> currentId,
-                                            @Nonnull DataObject parentData) {
-        return Optional.fromNullable((((Ipv4) parentData).getNeighbor()));
-    }
-
     private void addDelNeighbourAndReply(InstanceIdentifier<Neighbor> id, boolean add, int parentInterfaceIndex,
                                          Neighbor data)
             throws VppBaseCallException, WriteTimeoutException {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv6Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv6Customizer.java
index 0fe86435e..d43bc90d5 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv6Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/Ipv6Customizer.java
@@ -16,20 +16,17 @@
 
 package io.fd.honeycomb.v3po.translate.v3po.interfaces.ip;
 
-import com.google.common.base.Optional;
-import io.fd.honeycomb.v3po.translate.spi.write.ChildWriterCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.write.WriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import javax.annotation.Nonnull;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.Interface1;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.interfaces._interface.Ipv6;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class Ipv6Customizer extends FutureJVppCustomizer implements ChildWriterCustomizer<Ipv6> {
+public class Ipv6Customizer extends FutureJVppCustomizer implements WriterCustomizer<Ipv6> {
 
     private static final Logger LOG = LoggerFactory.getLogger(Ipv6Customizer.class);
 
@@ -37,13 +34,6 @@ public class Ipv6Customizer extends FutureJVppCustomizer implements ChildWriterC
         super(vppApi);
     }
 
-    @Nonnull
-    @Override
-    public Optional<Ipv6> extract(@Nonnull final InstanceIdentifier<Ipv6> currentId,
-                                      @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((Interface1) parentData).getIpv6());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<Ipv6> id,
                                        @Nonnull final Ipv6 dataAfter, @Nonnull final WriteContext writeContext) {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/SubInterfaceIpv4AddressCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/SubInterfaceIpv4AddressCustomizer.java
index ccdcc6ce2..3d41b899f 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/SubInterfaceIpv4AddressCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfaces/ip/SubInterfaceIpv4AddressCustomizer.java
@@ -20,27 +20,23 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static io.fd.honeycomb.v3po.translate.v3po.interfaces.ip.Ipv4WriteUtils.addDelAddress;
 import static io.fd.honeycomb.v3po.translate.v3po.interfaces.ip.Ipv4WriteUtils.getSubnetMaskLength;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.InterfaceKey;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.DottedQuad;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterface;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterfaceKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.ip4.attributes.Ipv4;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.ip4.attributes.ipv4.Address;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.ip4.attributes.ipv4.AddressKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.ip4.attributes.ipv4.address.Subnet;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.ip4.attributes.ipv4.address.subnet.Netmask;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.ip4.attributes.ipv4.address.subnet.PrefixLength;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.future.FutureJVpp;
@@ -81,11 +77,6 @@ public class SubInterfaceIpv4AddressCustomizer extends FutureJVppCustomizer
         setAddress(false, id, dataBefore, writeContext);
     }
 
-    @Override
-    public Optional<List<Address>> extract(InstanceIdentifier<Address> currentId, DataObject parentData) {
-        return Optional.fromNullable((((Ipv4) parentData).getAddress()));
-    }
-
     private void setAddress(boolean add, final InstanceIdentifier<Address> id, final Address address,
                             final WriteContext writeContext) throws WriteFailedException {
 
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/AclCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/AclCustomizer.java
index d8d2d8e30..c5b17e5b9 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/AclCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/AclCustomizer.java
@@ -21,7 +21,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
@@ -42,10 +42,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Customizer for reading ACLs enabled on given interface
+ * Customizer for reading ACLs enabled on given interface.
  */
 public class AclCustomizer extends FutureJVppCustomizer
-    implements ChildReaderCustomizer<Acl, AclBuilder>, AclReader {
+    implements ReaderCustomizer<Acl, AclBuilder>, AclReader {
 
     private static final Logger LOG = LoggerFactory.getLogger(AclCustomizer.class);
     private final NamingContext interfaceContext;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/EthernetCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/EthernetCustomizer.java
index 5bbf33935..a2643e408 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/EthernetCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/EthernetCustomizer.java
@@ -18,7 +18,7 @@ package io.fd.honeycomb.v3po.translate.v3po.interfacesstate;
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import javax.annotation.Nonnull;
@@ -37,7 +37,7 @@ import org.slf4j.LoggerFactory;
 
 
 public class EthernetCustomizer extends FutureJVppCustomizer
-        implements ChildReaderCustomizer<Ethernet, EthernetBuilder> {
+        implements ReaderCustomizer<Ethernet, EthernetBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(EthernetCustomizer.class);
     private NamingContext interfaceContext;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/L2Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/L2Customizer.java
index e1496e36b..e7c6b2aa1 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/L2Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/L2Customizer.java
@@ -18,7 +18,7 @@ package io.fd.honeycomb.v3po.translate.v3po.interfacesstate;
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface;
@@ -34,15 +34,13 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.annotation.Nonnull;
-import java.util.Optional;
-import java.util.concurrent.CompletableFuture;
 
 import static com.google.common.base.Preconditions.checkState;
 
 /**
  * Customizer for reading ietf-interfaces:interfaces-state/interface/iface_name/v3po:l2
  */
-public class L2Customizer extends FutureJVppCustomizer implements ChildReaderCustomizer<L2, L2Builder> {
+public class L2Customizer extends FutureJVppCustomizer implements ReaderCustomizer<L2, L2Builder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(L2Customizer.class);
     private final InterconnectionReadUtils icReadUtils;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/RewriteCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/RewriteCustomizer.java
index 9bb12da82..e76ed7662 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/RewriteCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/RewriteCustomizer.java
@@ -21,7 +21,7 @@ import static com.google.common.base.Preconditions.checkState;
 import com.google.common.base.Preconditions;
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils;
@@ -57,7 +57,7 @@ import org.slf4j.LoggerFactory;
  * Customizer for reading vlan tag-rewrite configuration state form the VPP.
  */
 public class RewriteCustomizer extends FutureJVppCustomizer
-        implements ChildReaderCustomizer<Rewrite, RewriteBuilder> {
+        implements ReaderCustomizer<Rewrite, RewriteBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(RewriteCustomizer.class);
     private final NamingContext interfaceContext;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceAclCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceAclCustomizer.java
index a00485f49..276849ba4 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceAclCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceAclCustomizer.java
@@ -22,7 +22,7 @@ import static io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils.getSubI
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
@@ -45,10 +45,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Customizer for reading ACLs enabled on given sub-interface
+ * Customizer for reading ACLs enabled on given sub-interface.
  */
 public class SubInterfaceAclCustomizer extends FutureJVppCustomizer
-    implements ChildReaderCustomizer<Acl, AclBuilder>, AclReader {
+    implements ReaderCustomizer<Acl, AclBuilder>, AclReader {
 
     private static final Logger LOG = LoggerFactory.getLogger(SubInterfaceAclCustomizer.class);
     private final NamingContext interfaceContext;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceL2Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceL2Customizer.java
index 0c6d50b76..6e9b16719 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceL2Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/SubInterfaceL2Customizer.java
@@ -20,7 +20,7 @@ import static io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils.getSubI
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import javax.annotation.Nonnull;
@@ -41,7 +41,7 @@ import org.slf4j.LoggerFactory;
 /**
  * Customizer for reading vlan sub interface L2 operational state
  */
-public class SubInterfaceL2Customizer extends FutureJVppCustomizer implements ChildReaderCustomizer<L2, L2Builder> {
+public class SubInterfaceL2Customizer extends FutureJVppCustomizer implements ReaderCustomizer<L2, L2Builder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(SubInterfaceL2Customizer.class);
     private final InterconnectionReadUtils icReadUtils;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/TapCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/TapCustomizer.java
index 3f79e5517..c9a592e30 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/TapCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/TapCustomizer.java
@@ -20,7 +20,7 @@ import static io.fd.honeycomb.v3po.translate.v3po.interfacesstate.InterfaceUtils
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
@@ -48,7 +48,7 @@ import org.slf4j.LoggerFactory;
 
 
 public class TapCustomizer extends FutureJVppCustomizer
-        implements ChildReaderCustomizer<Tap, TapBuilder> {
+        implements ReaderCustomizer<Tap, TapBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(TapCustomizer.class);
     public static final String DUMPED_TAPS_CONTEXT_KEY = TapCustomizer.class.getName() + "dumpedTapsDuringGetAllIds";
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VhostUserCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VhostUserCustomizer.java
index 23e1a6efd..878eb3179 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VhostUserCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VhostUserCustomizer.java
@@ -20,7 +20,7 @@ import static io.fd.honeycomb.v3po.translate.v3po.interfacesstate.InterfaceUtils
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
@@ -50,7 +50,7 @@ import org.slf4j.LoggerFactory;
 
 
 public class VhostUserCustomizer extends FutureJVppCustomizer
-        implements ChildReaderCustomizer<VhostUser, VhostUserBuilder> {
+        implements ReaderCustomizer<VhostUser, VhostUserBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(VhostUserCustomizer.class);
     public static final String DUMPED_VHOST_USERS_CONTEXT_KEY = VhostUserCustomizer.class.getName() + "dumpedVhostUsersDuringGetAllIds";
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanCustomizer.java
index 3d82820a4..b57274a88 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanCustomizer.java
@@ -21,7 +21,7 @@ import static io.fd.honeycomb.v3po.translate.v3po.interfacesstate.InterfaceUtils
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
@@ -52,10 +52,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class VxlanCustomizer extends FutureJVppCustomizer
-        implements ChildReaderCustomizer<Vxlan, VxlanBuilder> {
+        implements ReaderCustomizer<Vxlan, VxlanBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(VxlanCustomizer.class);
-    private NamingContext interfaceContext;
+    private final NamingContext interfaceContext;
 
     public VxlanCustomizer(@Nonnull final FutureJVpp jvpp, @Nonnull final NamingContext interfaceContext) {
         super(jvpp);
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanGpeCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanGpeCustomizer.java
index de05dc4bc..2e45a2b64 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanGpeCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/VxlanGpeCustomizer.java
@@ -21,7 +21,7 @@ import static io.fd.honeycomb.v3po.translate.v3po.interfacesstate.InterfaceUtils
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
@@ -53,7 +53,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class VxlanGpeCustomizer extends FutureJVppCustomizer
-        implements ChildReaderCustomizer<VxlanGpe, VxlanGpeBuilder> {
+        implements ReaderCustomizer<VxlanGpe, VxlanGpeBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(VxlanGpeCustomizer.class);
     private NamingContext interfaceContext;
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv4Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv4Customizer.java
index 8e6162784..fa912c05e 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv4Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv4Customizer.java
@@ -18,7 +18,7 @@ package io.fd.honeycomb.v3po.translate.v3po.interfacesstate.ip;
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.ip.rev140616.Interface2Builder;
@@ -31,7 +31,7 @@ import org.openvpp.jvpp.future.FutureJVpp;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class Ipv4Customizer extends FutureJVppCustomizer implements ChildReaderCustomizer<Ipv4, Ipv4Builder> {
+public class Ipv4Customizer extends FutureJVppCustomizer implements ReaderCustomizer<Ipv4, Ipv4Builder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(Ipv4Customizer.class);
 
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv6Customizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv6Customizer.java
index 37524dde6..ada05b72f 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv6Customizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/interfacesstate/ip/Ipv6Customizer.java
@@ -17,7 +17,7 @@ package io.fd.honeycomb.v3po.translate.v3po.interfacesstate.ip;
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
 import javax.annotation.Nonnull;
@@ -29,7 +29,7 @@ import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.future.FutureJVpp;
 
-public class Ipv6Customizer extends FutureJVppCustomizer implements ChildReaderCustomizer<Ipv6, Ipv6Builder> {
+public class Ipv6Customizer extends FutureJVppCustomizer implements ReaderCustomizer<Ipv6, Ipv6Builder> {
 
     private final NamingContext interfaceContext;
 
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/BridgeDomainCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/BridgeDomainCustomizer.java
index 22344baa6..601a79eba 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/BridgeDomainCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/BridgeDomainCustomizer.java
@@ -20,7 +20,6 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;
 
-import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
@@ -29,12 +28,9 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import javax.annotation.Nonnull;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.vpp.BridgeDomains;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.vpp.bridge.domains.BridgeDomain;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.vpp.bridge.domains.BridgeDomainKey;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.BridgeDomainAddDel;
@@ -57,13 +53,6 @@ public class BridgeDomainCustomizer
         this.bdContext = Preconditions.checkNotNull(bdContext, "bdContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<List<BridgeDomain>> extract(@Nonnull final InstanceIdentifier<BridgeDomain> currentId,
-                                                @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((BridgeDomains) parentData).getBridgeDomain());
-    }
-
     private BridgeDomainAddDelReply addOrUpdateBridgeDomain(@Nonnull final InstanceIdentifier<BridgeDomain> id,
                                                             final int bdId, @Nonnull final BridgeDomain bd)
         throws VppBaseCallException, WriteTimeoutException {
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/L2FibEntryCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/L2FibEntryCustomizer.java
index 3655a48f1..52bb1ad61 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/L2FibEntryCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vpp/L2FibEntryCustomizer.java
@@ -19,7 +19,6 @@ package io.fd.honeycomb.v3po.translate.v3po.vpp;
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.parseMac;
 
-import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import com.google.common.primitives.Longs;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
@@ -29,16 +28,13 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import java.util.concurrent.CompletionStage;
 import javax.annotation.Nonnull;
 import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.L2FibFilter;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.l2.fib.attributes.L2FibTable;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.l2.fib.attributes.l2.fib.table.L2FibEntry;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.l2.fib.attributes.l2.fib.table.L2FibEntryKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.vpp.bridge.domains.BridgeDomain;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.L2FibAddDel;
@@ -66,13 +62,6 @@ public class L2FibEntryCustomizer extends FutureJVppCustomizer
         this.interfaceContext = Preconditions.checkNotNull(interfaceContext, "interfaceContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<List<L2FibEntry>> extract(@Nonnull final InstanceIdentifier<L2FibEntry> currentId,
-                                              @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((L2FibTable) parentData).getL2FibEntry());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<L2FibEntry> id,
                                        @Nonnull final L2FibEntry dataAfter, @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifySessionWriter.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifySessionWriter.java
index ac964a9b8..ea183a839 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifySessionWriter.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifySessionWriter.java
@@ -21,7 +21,6 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
@@ -29,7 +28,6 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import java.util.concurrent.CompletionStage;
 import javax.annotation.Nonnull;
 import javax.xml.bind.DatatypeConverter;
@@ -38,7 +36,6 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.clas
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.classify.table.base.attributes.ClassifySessionKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.ClassifyTable;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.ClassifyTableKey;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.ClassifyAddDelSession;
@@ -63,13 +60,6 @@ public class ClassifySessionWriter extends FutureJVppCustomizer
         this.classifyTableContext = checkNotNull(classifyTableContext, "classifyTableContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<List<ClassifySession>> extract(@Nonnull final InstanceIdentifier<ClassifySession> currentId,
-                                                   @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((ClassifyTable) parentData).getClassifySession());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<ClassifySession> id,
                                        @Nonnull final ClassifySession dataAfter,
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifyTableWriter.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifyTableWriter.java
index 788aac59c..c34468458 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifyTableWriter.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppclassifier/ClassifyTableWriter.java
@@ -21,7 +21,6 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;
 
-import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.translate.MappingContext;
 import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
@@ -30,14 +29,11 @@ import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import io.fd.honeycomb.v3po.translate.v3po.util.WriteTimeoutException;
 import io.fd.honeycomb.v3po.translate.write.WriteContext;
 import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
-import java.util.List;
 import java.util.concurrent.CompletionStage;
 import javax.annotation.Nonnull;
 import javax.xml.bind.DatatypeConverter;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.VppClassifier;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.ClassifyTable;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.ClassifyTableKey;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.openvpp.jvpp.VppBaseCallException;
 import org.openvpp.jvpp.dto.ClassifyAddDelTable;
@@ -62,13 +58,6 @@ public class ClassifyTableWriter extends FutureJVppCustomizer
         this.classifyTableContext = checkNotNull(classifyTableContext, "classifyTableContext should not be null");
     }
 
-    @Nonnull
-    @Override
-    public Optional<List<ClassifyTable>> extract(@Nonnull final InstanceIdentifier<ClassifyTable> currentId,
-                                                 @Nonnull final DataObject parentData) {
-        return Optional.fromNullable(((VppClassifier) parentData).getClassifyTable());
-    }
-
     @Override
     public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<ClassifyTable> id,
                                        @Nonnull final ClassifyTable dataAfter, @Nonnull final WriteContext writeContext)
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppstate/VersionCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppstate/VersionCustomizer.java
index 83a8995f7..2032cd811 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppstate/VersionCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/v3po/translate/v3po/vppstate/VersionCustomizer.java
@@ -18,7 +18,7 @@ package io.fd.honeycomb.v3po.translate.v3po.vppstate;
 
 import io.fd.honeycomb.v3po.translate.read.ReadContext;
 import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
-import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
 import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
 import java.util.concurrent.CompletionStage;
@@ -36,7 +36,7 @@ import org.openvpp.jvpp.future.FutureJVpp;
 
 public final class VersionCustomizer
     extends FutureJVppCustomizer
-    implements ChildReaderCustomizer<Version, VersionBuilder> {
+    implements ReaderCustomizer<Version, VersionBuilder> {
 
     /**
      * Default timeout for executing version read