####################
#    class node
####################
"Double linked list"
class Node:
    def __init__(self, previous=None, next=None, data=None):
        self.previous = previous
        self.next = next
        self.data = data

    def getNext(self):
        return self.next

    def getPrevious(self):
        return self.previous

    def getData(self):
        return self.data

    def setData(self, data):
        self.data = data

    def setNext(self, next):
        self.next = next
        
    def setPrevious(self, previous):
        self.previous = previous