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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def insert(self, key):
 """ Insert new key into node """

        # Create new node
        n = TreeNode(key)
        if not self.node:
            self.node = n
            self.node.left = AvlTree()
            self.node.right = AvlTree()
        elif key < self.node.val:
            self.node.left.insert(key)
        elif key > self.node.val:
            self.node.right.insert(key)
        self.re_balance()