public void AddByIndex(int index, int value)
{
CheckBounds(index);
DoubleNode DoubleNode = new DoubleNode(value);
DoubleNode.AttachBefore(FindDoubleNode(index));
Length++;
}
public void Add(int value)
{
DoubleNode tmp = new DoubleNode(value);
tmp.Previous = _root.Previous;
tmp.AttachBefore(_root);
Length++;
}