private PromiseActorRef createActorRef() {
ActorRefProvider refProvider = mock(ActorRefProvider.class, RETURNS_DEFAULTS);
@SuppressWarnings("unchecked")
Promise<Object> promise = mock(Promise.class, RETURNS_SMART_NULLS);
PromiseActorRef ref = new PromiseActorRef(refProvider, promise);
return ref;
}