testBigShift() {
    const a = Integer.fromString('3735928559');
    assertEquals(
        '591981510028266767381876356163880091648', a.shiftLeft(97).toString());
    assertEquals(
        '-591981510028266767381876356163880091648',
        a.negate().shiftLeft(97).toString());
  }
@suppress {visibility} suppression added to enable type
                    checking