public static void TestLl()
{
var list = new LinkedList <int>();
list.PushBack(5);
list.PushBack(4);
list.Push(11);
list.PushBack(7);
list.PushBack(1);
Output(list);
list.Insert(4, 6);
Output(list);
var list2 = new LinkedList <int>();
list2.PushBack(11);
list2.PushBack(12);
list2.Push(19);
list.AddAll(list2);
Output(list);
new Sorter <int>(SortType.Dsc).MergeSort(list);
Output(list);
Console.WriteLine("Complete.");
}