Construct GraphDescription with online/active Device/Link only

Change-Id: I9312c0c8ae190bf0200bd040823b6f7a3e7a15e1
diff --git a/providers/lldp/src/test/java/org/onlab/onos/provider/lldp/impl/LLDPLinkProviderTest.java b/providers/lldp/src/test/java/org/onlab/onos/provider/lldp/impl/LLDPLinkProviderTest.java
index 4311bb4..3416da3 100644
--- a/providers/lldp/src/test/java/org/onlab/onos/provider/lldp/impl/LLDPLinkProviderTest.java
+++ b/providers/lldp/src/test/java/org/onlab/onos/provider/lldp/impl/LLDPLinkProviderTest.java
@@ -37,7 +37,7 @@
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.device.DeviceEvent;
 import org.onlab.onos.net.device.DeviceListener;
-import org.onlab.onos.net.device.DeviceService;
+import org.onlab.onos.net.device.DeviceServiceAdapter;
 import org.onlab.onos.net.flow.TrafficTreatment;
 import org.onlab.onos.net.link.LinkDescription;
 import org.onlab.onos.net.link.LinkProvider;
@@ -376,7 +376,7 @@
         }
     }
 
-    private class TestDeviceService implements DeviceService {
+    private class TestDeviceService extends DeviceServiceAdapter {
 
         private Map<DeviceId, Device> devices = new HashMap<>();
         private final ArrayListMultimap<DeviceId, Port> ports =
@@ -408,7 +408,7 @@
 
         @Override
         public Iterable<Device> getDevices() {
-            return Collections.EMPTY_LIST;
+            return Collections.emptyList();
         }
 
         @Override