public void FreeDynamicSet()
        {
            var s = UnsafeHashSet.Allocate <int>(2, false);

            UnsafeHashSet.Free(s);
        }
        public void FreeFixedSet()
        {
            var s = UnsafeHashSet.Allocate <int>(2, true);

            UnsafeHashSet.Free(s);
        }