private static Throwable moreImportant(Throwable throwable1, Throwable throwable2) {
    Throwable result;
    if (throwable1 == null) {
      result = throwable2;
    }
    else if (throwable2 == null) {
      result = throwable1;
    }
    else {
      // any exception wins over PCE because the latter can be induced by canceled indicator because of the former
      result = throwable1 instanceof ProcessCanceledException ? throwable2 : throwable1;
    }
    return result;
  }
private static Throwable moreImportant(Throwable throwable1, Throwable throwable2)