1 files changed, 29 insertions, 3 deletions
diff --git a/v3po/impl/src/main/java/io/fd/honeycomb/v3po/impl/trans/w/WriteContext.java b/v3po/impl/src/main/java/io/fd/honeycomb/v3po/impl/trans/w/WriteContext.java
index 49759f20f..3aaf83250 100644
--- a/v3po/impl/src/main/java/io/fd/honeycomb/v3po/impl/trans/w/WriteContext.java
+++ b/v3po/impl/src/main/java/io/fd/honeycomb/v3po/impl/trans/w/WriteContext.java
@@ -16,16 +16,42 @@
 
 package io.fd.honeycomb.v3po.impl.trans.w;
 
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
 import io.fd.honeycomb.v3po.impl.trans.util.Context;
-import java.util.List;
+import javax.annotation.Nonnull;
 import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 
+/**
+ * Context providing information about current state of DataTree to writers
+ */
+@Beta
 public interface WriteContext {
 
-    List<? extends DataObject> readBefore(InstanceIdentifier<? extends DataObject> currentId);
+    /**
+     * Read any data object before current modification was applied
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data before the modification was applied
+     */
+    Optional<DataObject> readBefore(@Nonnull final InstanceIdentifier<? extends DataObject> currentId);
 
-    List<? extends DataObject> readAfter(InstanceIdentifier<? extends DataObject> currentId);
+    /**
+     * Read any data object from current modification
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data from the modification
+     */
+    Optional<DataObject> readAfter(@Nonnull final InstanceIdentifier<? extends DataObject> currentId);
 
+    /**
+     * Get key value storage for customizers
+     *
+     * @return Context for customizers
+     */
+    @Nonnull
     Context getContext();
 }