CORD-131 Added XOS vtn service and port APIs

Change-Id: Ide34212eeb593af5af8db218c6dd2af7d5ab4eaa
diff --git a/apps/xosclient/src/main/java/org/onosproject/xosclient/api/VtnServiceId.java b/apps/xosclient/src/main/java/org/onosproject/xosclient/api/VtnServiceId.java
new file mode 100644
index 0000000..5850696
--- /dev/null
+++ b/apps/xosclient/src/main/java/org/onosproject/xosclient/api/VtnServiceId.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2016-present 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.xosclient.api;
+
+import org.onlab.util.Identifier;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Representation of VTN service identifier.
+ */
+public final class VtnServiceId extends Identifier<String> {
+    /**
+     * Default constructor.
+     *
+     * @param id service identifier
+     */
+    private VtnServiceId(String id) {
+        super(id);
+    }
+
+    /**
+     * Returns the VtnServiceId with value.
+     *
+     * @param id service id
+     * @return CordServiceId
+     */
+    public static VtnServiceId of(String id) {
+        checkNotNull(id);
+        return new VtnServiceId(id);
+    }
+}