@DoNotSub public int hashCode()
    {
        @DoNotSub int hashCode = 0;
        for (final int value : values)
        {
            if (MISSING_VALUE != value)
            {
                hashCode += Integer.hashCode(value);
            }
        }

        if (containsMissingValue)
        {
            hashCode += Integer.hashCode(MISSING_VALUE);
        }

        return hashCode;
    }
@Test
    void twoEmptySetsHaveTheSameHashcode()
    {
        assertEquals(testSet.hashCode(), new IntHashSet(100).hashCode());
    }