+ verify(mockClusterSingletonService, never()).closeServiceInstance();
+ singletonServiceGroup.ownershipChanged(getEntityToSlaveNoMaster());
+ verify(mockClusterSingletonService, atLeastOnce()).closeServiceInstance();
+ final ClusterSingletonServiceGroup<?, ?, ?> serviceGroup = map.get(SERVICE_IDENTIFIER);
+ Assert.assertNull(serviceGroup);