list mastership roles CLI command

Change-Id: I54dc296f90c4b8ceebe4e86816c3796da4d2d714
diff --git a/core/api/src/test/java/org/onlab/onos/mastership/MastershipServiceAdapter.java b/core/api/src/test/java/org/onlab/onos/mastership/MastershipServiceAdapter.java
index 97b57e5..af376e8 100644
--- a/core/api/src/test/java/org/onlab/onos/mastership/MastershipServiceAdapter.java
+++ b/core/api/src/test/java/org/onlab/onos/mastership/MastershipServiceAdapter.java
@@ -4,6 +4,7 @@
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.MastershipRole;
 
+import java.util.List;
 import java.util.Set;
 
 /**
@@ -46,4 +47,9 @@
     public MastershipTermService requestTermService() {
         return null;
     }
+
+    @Override
+    public List<NodeId> getNodesFor(DeviceId deviceId) {
+        return null;
+    }
 }