Construct GraphDescription with online/active Device/Link only

Change-Id: I9312c0c8ae190bf0200bd040823b6f7a3e7a15e1
diff --git a/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java b/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java
index f67d992..175a299 100644
--- a/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java
+++ b/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java
@@ -20,6 +20,7 @@
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import com.google.common.util.concurrent.ListenableFuture;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -34,7 +35,7 @@
 import org.onlab.onos.net.Port;
 import org.onlab.onos.net.PortNumber;
 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.BatchOperation;
 import org.onlab.onos.net.flow.CompletedBatchOperation;
 import org.onlab.onos.net.flow.DefaultFlowEntry;
@@ -461,7 +462,7 @@
         }
     }
 
-    private static class TestDeviceService implements DeviceService {
+    private static class TestDeviceService extends DeviceServiceAdapter {
 
         @Override
         public int getDeviceCount() {