[ONOS-4302] RPC translator implementation

Change-Id: I457f12a2b0edaadee5ff888e0297b40854d53096
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java
index 4b9d7b5..def4cc9 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/UtilConstants.java
@@ -138,6 +138,21 @@
     public static final String BUILDER_OBJECT = "builder object of ";
 
     /**
+     * JavaDocs's statement for rpc method.
+     */
+    public static final String JAVA_DOC_RPC = " * Service interface of ";
+
+    /**
+     * JavaDocs's statement for rpc's input string.
+     */
+    public static final String RPC_INPUT_STRING = "input of service interface ";
+
+    /**
+     * JavaDocs's statement for rpc's output string.
+     */
+    public static final String RPC_OUTPUT_STRING = "output of service interface ";
+
+    /**
      * Static attribute for new line.
      */
     public static final String NEW_LINE = "\n";
@@ -218,6 +233,11 @@
     public static final String INPUT = "input";
 
     /**
+     * Static attribute for output variable of rpc.
+     */
+    public static final String RPC_INPUT_VAR_NAME = "inputVar";
+
+    /**
      * Static attribute for new line.
      */
     public static final String EQUAL = "=";
@@ -723,6 +743,11 @@
     public static final String EXTEND = "extends";
 
     /**
+     * Static attribute for service interface suffix syntax.
+     */
+    public static final String SERVICE_METHOD_STRING = "Service";
+
+    /**
      * Static attribute for impl syntax.
      */
     public static final String IMPL = "Impl";