public static void TestFindAll <T, Index2DCollection, TPredicate>(
List2D <T> list, TPredicate match, Index2DCollection expected)
where Index2DCollection : ICollection <Index2D>, new()
where TPredicate : struct, IPredicate <T>
=> CollectionAssert.AreEqual(
expected, list.FindAllIndices <Index2DCollection, TPredicate>(match));
