please complete, the uncompleted python program. the sample code is also there. but beware, that is sample, just abit similar. thanks

Develop a Doubly-Linked-List, with the given Python file A1B2 py. - Each node in Doubly-Linked-List has two links: one for the next node as in singly-linked list, the other for the previous node. The head node has no previous link and the tail node has no next link. This is implemented as a Python class DLNode and given in our Python file. - Some operations could be done for efficiently with this Doubly-Linked-List, which require tracing backward (the previous node of the current node). - Given an uncompleted Doubly-Linked-List in A1B2.py (based on the one in our lecture notes, LList.py), with implemented methods below: - Complete this Doubly-Linked-List with the Extra Operations below (methods of the class): - At least one line of simple comment for each extra operation required Sample console display output of executing the main testing program MA1B2.pY -.- 1. List with Insert items 20,30,40,50,60,70 >>> DOUBLY-Linked-List Display: > head 20, tail 70 : >20>30>40>50>60>70 DoUBLY-Linked-List Display, Backwards: FROM ... tail 70, head 20 removeNextFwDL(30), elt:40 >>> DOUBLY-Linked-List Display: > head 20, tail 70 : >20>30>50>60>70 DoUBLY-Linked-List Display, Backwards: FROM ... tail 70, head 20 curN. vatue ", end = ' ) curN = curN.nextN