private void AssertTargeted(Lazy <SortedSet <CellState> > cells, params int[] expectedIds)
{
var ids =
cells.Value.Select(x => int.Parse(x.Name.Substring(3)))
.ToArray();
Array.Sort(ids);
Array.Sort(expectedIds);
CollectionAssert.AreEquivalent(expectedIds, ids);
_instance.ClearCellCache();
}