final AbstractFuture<String> future = new AbstractFuture<String>() {};
      currentFuture.set(future);
      for (Callable<?> task : allTasks) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
        Future<?> possiblyIgnoredError = executor.submit(task);
      }
      awaitUnchecked(barrier);
      assertThat(future.isDone()).isTrue();

      final AbstractFuture<String> future = new AbstractFuture<String>() {};
      currentFuture.set(future);
      for (Callable<?> task : allTasks) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
        Future<?> possiblyIgnoredError = executor.submit(task);
      }
      awaitUnchecked(barrier);
      assertThat(future.isDone()).isTrue();