7. (3 pts) Write an algorithm for the implementation of the method swap_ends() of the DLLDeque data structure below. DLLDeque implements the Deque interface using a doubly- linked list. The method swap_ends() swaps the node (not just the data) at the head of the list with the node at the tail of the list. 1 from Interfaces import Deque 2 3 class DLLDeque(Deque): 4 class Node: s def__init_(self, x : object): 6 self.X =x 7 self.next = None 8 self.prev = None 8 10 def__init_(self): 11 self.dummy = DLList.Node(None) 12 self.dummy.next = dummy 13 self.dummy.prev = dummy 14 self.n =0 15 return 16 17 18 10 def swap_ends(self): 20 \# todo 21 return 1 from Interfaces import Deque 2 3 class DLLDeque(Deque): 4 class Node: s def__init_(self, x : object): 6 self. x=x 7 self. next = None 8 self. prev = None 10 def__init_(self): 11 self.dummy = DLList. Node( None ) 12 self.dummy. next = dummy 1 s self.dummy prev = dummy 14 self. n=0 15 return 16 17 18 10 def swap_ends(self): 20 \# todo 21 return.