List<T> list = Arrays.asList(inputs);
    doExpectCollects(expectedResult, list);
    if (collector.characteristics().contains(Collector.Characteristics.UNORDERED)) {
      Collections.reverse(list);
      doExpectCollects(expectedResult, list);
    }
    return this;
  }

  private void doExpectCollects(R expectedResult, List<T> inputs) {