Adds unit test for OpenstackRoutingIcmpHandler.

Change-Id: I764aa769c25a21ff410fa431cdc7552d6af1c059
diff --git a/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/TestRouterInterface.java b/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/TestRouterInterface.java
new file mode 100644
index 0000000..c23ccd8
--- /dev/null
+++ b/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/TestRouterInterface.java
@@ -0,0 +1,56 @@
+/*
+ * 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.openstacknetworking.impl;
+
+import org.openstack4j.model.network.RouterInterface;
+
+/**
+ * Test implementation class of router interface.
+ */
+public final class TestRouterInterface implements RouterInterface {
+    private final String id;
+    private final String subnetId;
+    private final String portId;
+    private final String tenantId;
+
+    public TestRouterInterface(String id, String subnetId,
+                               String portId, String tenantId) {
+        this.id = id;
+        this.subnetId = subnetId;
+        this.portId = portId;
+        this.tenantId = tenantId;
+    }
+
+    @Override
+    public String getId() {
+        return id;
+    }
+
+    @Override
+    public String getSubnetId() {
+        return subnetId;
+    }
+
+    @Override
+    public String getPortId() {
+        return portId;
+    }
+
+    @Override
+    public String getTenantId() {
+        return tenantId;
+    }
+}