assertThrows(ArithmeticException.class, () -> DoubleMath.roundToLong(d, UNNECESSARY));
    }
  }

  @GwtIncompatible // DoubleMath.roundToLong(double, RoundingMode)
  public void testRoundNaNToLongAlwaysFails() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertThrows(ArithmeticException.class, () -> DoubleMath.roundToLong(Double.NaN, mode));
    }
  }