public void IsProperSupersetOf_NullOther_ArgumentNullException()
 => Assert.Catch <ArgumentNullException>(() => _filledIntSet.IsProperSupersetOf(null));
        public bool IsProperSupersetOf_IntValues_CorrectResult(int[] subset, int[] set)
        {
            AddValues(subset);

            return(_intSet.IsProperSupersetOf(set));
        }