@Test
public void shouldReturnServiceUnavailableWithNoLocationIfCompareAndSetFailsBecauseNotLeaderExceptionIsThrownWithTheLeaderSetToNull() {

    when(distributedStore.compareAndSet(KEY, casValue)).thenReturn(Futures.<KeyValue>immediateFailedFuture(new NotLeaderException(self, null)));
    assertThatValidCompareAndSetRequestReturnsErrorStatus(ClientResponse.Status.SERVICE_UNAVAILABLE);
}