+import org.opendaylight.yangtools.yang.model.api.ChoiceCaseNode;
+import org.opendaylight.yangtools.yang.model.api.ChoiceSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.ContainerSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
+import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.GroupingDefinition;
+import org.opendaylight.yangtools.yang.model.api.ListSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.Module;
+import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
+import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
+import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
+
+/**
+ * DataNodeIterator is iterator, which walks down whole YANG DataNodeContainer
+ * and walks all instances of {@link DataSchemaNode} present in subtree.
+ *
+ * Iterator instance is eagerly created, walking happens on initialization.
+ *
+ * Iteration is not ordered.
+ *
+ */