def insert(self,value):
        if (self.curr and self.head) == None:
            self.curr = Node(self.head,value,self.tail)
            self.tail = Node(self.curr, None, None)
            self.head = Node(None, None, self.curr)
        else:
            self.curr = Node(self.curr,value,self.tail)
            self.curr.prev.next = self.curr
            self.tail.prev = self.curr

        self.size += 1