MaybeCallbackObserver extends AtomicReference<Disposable> implements MaybeObserver<T>, Disposable, LambdaConsumerIntrospection { @Override public void dispose() { DisposableHelper.dispose(this); } MaybeCallbackObserver(Consumer<? super T> onSuccess, Consumer<? super Throwable> onError,
            Action onComplete); @Override void dispose(); @Override boolean isDisposed(); @Override void onSubscribe(Disposable d); @Override void onSuccess(T value); @Override void onError(Throwable e); @Override void onComplete(); @Override boolean hasCustomOnError();  }
@Test public void dispose() { MaybeCallbackObserver<Object> mo = new MaybeCallbackObserver<Object>(Functions.emptyConsumer(), Functions.emptyConsumer(), Functions.EMPTY_ACTION); Disposable d = Disposables.empty(); mo.onSubscribe(d); assertFalse(mo.isDisposed()); mo.dispose(); assertTrue(mo.isDisposed()); assertTrue(d.isDisposed()); }