def insertNode(self, afterNode, newData):
        newNode = Node(newData)

        if afterNode is None:
            return

        nextNode = afterNode.next
        afterNode.next = newNode
        newNode.next = nextNode
        self.size += 1
    def insertHead(self, newData):
        newNode = Node(newData)

        if self.head is None:
            self.head = newNode
            self.size += 1
            return

        newNode.next = self.head
        self.head = newNode