public void ClearNonAlloc() { // add some grid.Add(Vector2Int.zero, 1); grid.Add(Vector2Int.zero, 2); // clear and check if empty now grid.ClearNonAlloc(); HashSet <int> result = new HashSet <int>(); grid.GetWithNeighbours(Vector2Int.zero, result); Assert.That(result.Count, Is.EqualTo(0)); }