1 files changed, 19 insertions, 0 deletions
diff --git a/netmodel/model/key.py b/netmodel/model/key.py
new file mode 100644
index 00000000..bc49af03
--- /dev/null
+++ b/netmodel/model/key.py
@@ -0,0 +1,19 @@
+from netmodel.model.mapper         import ObjectSpecification
+
+class Key(ObjectSpecification):
+    def __init__(self, *attributes):
+        self._attributes = attributes
+
+    #--------------------------------------------------------------------------
+    # Descriptor protocol
+    #
+    # see. https://docs.python.org/3/howto/descriptor.html
+    #--------------------------------------------------------------------------
+
+    def __set_name__(self, owner, name):
+        self._name = name
+        self._owner = owner
+
+    def __iter__(self):
+        for attribute in self._attributes:
+            yield attribute