static UnsafeHashSet *Set(params int[] values)
        {
            var c = UnsafeHashSet.Allocate <int>(values.Length * 2);

            for (int i = 0; i < values.Length; ++i)
            {
                UnsafeHashSet.Add(c, values[i]);
            }

            return(c);
        }
        public void ClearHashSet()
        {
            var set = Set(1, 2, 3);

            IsTrue(UnsafeHashSet.Contains(set, 2));
            IsTrue(UnsafeHashSet.Count(set) == 3);

            UnsafeHashSet.Add(set, 4);
            IsTrue(UnsafeHashSet.Count(set) == 4);

            UnsafeHashSet.Clear(set);
            IsTrue(UnsafeHashSet.Count(set) == 0);
            IsTrue(!UnsafeHashSet.Contains(set, 2));

            UnsafeHashSet.Add(set, 4);
            IsTrue(UnsafeHashSet.Count(set) == 1);
            IsTrue(UnsafeHashSet.Contains(set, 4));

            UnsafeHashSet.Clear(set);
            IsTrue(UnsafeHashSet.Count(set) == 0);
        }