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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 _handle_expander_message(self, data):
 """ Handle expander messages. :param data: expander message to parse :type data: string :returns: :py:class:`~alarmdecoder.messages.ExpanderMessage` """

        msg = ExpanderMessage(data)

        self._update_internal_states(msg)
        self.on_expander_message(message=msg)

        return msg