for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(ZERO, BigIntegerMath.sqrt(ZERO, mode));
    }
  }

  @GwtIncompatible // TODO
  public void testSqrtNegativeAlwaysThrows() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertThrows(
          IllegalArgumentException.class, () -> BigIntegerMath.sqrt(BigInteger.valueOf(-1), mode));
    }
  }