[ONOS-7786] Support to retrieve metadata from virtual instances

Change-Id: Ieb3658ba06790b91cbe8b3075e0f64c5a86ee700
diff --git a/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/InstancePortServiceAdapter.java b/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/InstancePortServiceAdapter.java
index b0efdfa..d4f1d3f 100644
--- a/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/InstancePortServiceAdapter.java
+++ b/apps/openstacknetworking/app/src/test/java/org/onosproject/openstacknetworking/impl/InstancePortServiceAdapter.java
@@ -18,6 +18,8 @@
 import com.google.common.collect.ImmutableSet;
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
 import org.onosproject.openstacknetworking.api.InstancePort;
 import org.onosproject.openstacknetworking.api.InstancePortListener;
 import org.onosproject.openstacknetworking.api.InstancePortService;
@@ -44,6 +46,11 @@
     }
 
     @Override
+    public InstancePort instancePort(DeviceId deviceId, PortNumber portNumber) {
+        return null;
+    }
+
+    @Override
     public Set<InstancePort> instancePorts() {
         return ImmutableSet.of();
     }