Removes last

        :return: True iff last element has been removed

def remove_last(self):
        """Removes last

        :return: True iff last element has been removed
        """

        if self.length() <= 1:
            self.head = None
            return True

        node = self.head

        while node is not None:
            is_last_but_one = node.next_node is not None and \
                              node.next_node.next_node is None
            print(node.val, is_last_but_one)
            if is_last_but_one:  # this is the last
                node.next_node = None  # get to last but one element
                return True

            node = node.next_node

        return False