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));
    }
  }

  public void testSqrtZeroAlwaysZero() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(0, IntMath.sqrt(0, mode));
    }
  }

  @GwtIncompatible // sqrt
  public void testSqrtNegativeAlwaysThrows() {
    for (int x : NEGATIVE_INTEGER_CANDIDATES) {
      for (RoundingMode mode : RoundingMode.values()) {
        assertThrows(IllegalArgumentException.class, () -> IntMath.sqrt(x, mode));
      }
    }