[ONOS-3885, ONOS-3886, ONOS-3887] Implement YANG sub-module, container and list data model

Change-Id: Id9be89054db0f4c4f84e62547d3b6851cfed3de2
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/CodeGenerator.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/CodeGenerator.java
new file mode 100644
index 0000000..b0ed97c
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/translator/CodeGenerator.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator;
+
+/**
+ * Abstraction of an entity which provides Code generator functionalities.
+ */
+public interface CodeGenerator {
+
+    /**
+     * Traverse the schema of application and generate corresponding code.
+     */
+    void generateJavaCodeEntry();
+
+    /**
+     * Traverse the schema of application and generate corresponding code.
+     */
+    void generateJavaCodeExit();
+
+}