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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 pop(self):
 """ Removes the last node from the list """

        popped = False
        result = None
        current_node = self._first_node
        while not popped:
            next_node = current_node.next()
            next_next_node = next_node.next()
            if not next_next_node:
                self._last_node = current_node
                self._last_node.update_next(None)
                self._size -= 1
                result = next_node.data()
                popped = True
            current_node = next_node
        return result