Add Tapi Context/Topology/Node/Link builders and utility class

ONOS-7679

Change-Id: I85f856b11a5e272460b38c16ca46212fb4a0a082
diff --git a/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiContextBuilder.java b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiContextBuilder.java
new file mode 100644
index 0000000..2d24dc4
--- /dev/null
+++ b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiContextBuilder.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.odtn.utils.tapi;
+
+import org.onosproject.yang.gen.v1.tapicommon.rev20180307.tapicommon.DefaultContext;
+import org.onosproject.yang.gen.v1.tapicommon.rev20180307.tapicommon.Uuid;
+import org.onosproject.yang.model.ModelObject;
+import org.onosproject.yang.model.ModelObjectData;
+import org.onosproject.yang.model.ModelObjectId;
+
+/**
+ * Utility builder class for TAPI context creation with DCS.
+ */
+public final class TapiContextBuilder extends TapiInstanceBuilder {
+
+    private DefaultContext context;
+
+    private TapiContextBuilder(DefaultContext context) {
+        this.context = context;
+    }
+
+    public static TapiContextBuilder builder(DefaultContext context) {
+        return new TapiContextBuilder(context);
+    }
+
+    @Override
+    public ModelObjectData build() {
+        ModelObjectId objId = ModelObjectId.builder().build();
+        return getModelObjectData(context, objId);
+    }
+
+    @Override
+    public ModelObject getModelObject() {
+        return context;
+    }
+
+    @Override
+    public Uuid getUuid() {
+        return null;
+    }
+}