EmptyCompletableObserver extends AtomicReference<Disposable> implements CompletableObserver, Disposable, LambdaConsumerIntrospection { @Override public boolean hasCustomOnError() { return false; }  @Override void dispose(); @Override boolean isDisposed(); @Override void onComplete(); @Override void onError(Throwable e); @Override void onSubscribe(Disposable d); @Override boolean hasCustomOnError();  }
@Test public void defaultShouldReportNoCustomOnError() { EmptyCompletableObserver o = new EmptyCompletableObserver(); assertFalse(o.hasCustomOnError()); }