[S2GRAPH-216] Provide a transform directive in the GraphQL query result

JIRA:
  [S2GRAPH-216] https://issues.apache.org/jira/browse/S2GRAPH-216

Pull Request:
  Closes #168

Author
  daewon <daewon@apache.org>
diff --git a/CHANGES b/CHANGES
index b9bf81b..1f82a5e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -78,6 +78,7 @@
     * [S2GRAPH-210] - Rename package `mysqls` to `schema`
     * [S2GRAPH-213] - Abstract Query/Mutation from Storage.
     * [S2GRAPH-214] - Add REAME for movielens examples
+    * [S2GRAPH-216] - Provide a transform directive in the GraphQL query result.
 
 ** New Feature
     * [S2GRAPH-123] - Support different index on out/in direction.
diff --git a/s2graphql/src/main/scala/org/apache/s2graph/graphql/types/S2Directive.scala b/s2graphql/src/main/scala/org/apache/s2graph/graphql/types/S2Directive.scala
index 2eb5768..54512c1 100644
--- a/s2graphql/src/main/scala/org/apache/s2graph/graphql/types/S2Directive.scala
+++ b/s2graphql/src/main/scala/org/apache/s2graph/graphql/types/S2Directive.scala
@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.s2graph.graphql.types
 
 import sangria.schema.{Argument, Directive, DirectiveLocation, StringType}