Add atomic mastership/term/backups method to MastershipService

Change-Id: I18c3aeaa5101c9ce08ff38fffd70eaec903a0f3e
diff --git a/core/api/src/test/java/org/onosproject/mastership/MastershipServiceAdapter.java b/core/api/src/test/java/org/onosproject/mastership/MastershipServiceAdapter.java
index a0b203f..d9a2971 100644
--- a/core/api/src/test/java/org/onosproject/mastership/MastershipServiceAdapter.java
+++ b/core/api/src/test/java/org/onosproject/mastership/MastershipServiceAdapter.java
@@ -48,6 +48,11 @@
     }
 
     @Override
+    public MastershipInfo getMastershipFor(DeviceId deviceId) {
+        return null;
+    }
+
+    @Override
     public Set<DeviceId> getDevicesOf(NodeId nodeId) {
         return null;
     }