public void ignoreSynchronous() {
    pending.get().clear();
  }
@Test
  public void ignoreSynchronous() {
    var dispatcher = new EventDispatcher<Integer, Integer>(Runnable::run);
    dispatcher.pending.get().add(CompletableFuture.completedFuture(null));

    dispatcher.ignoreSynchronous();
    assertThat(dispatcher.pending.get()).isEmpty();
  }