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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 _recv_callback(self, msg):
 """ Method is called when there is a message coming from a Mongrel2 server. This message should be a valid Request String. """

        m2req = MongrelRequest.parse(msg[0])
        MongrelConnection(m2req, self._sending_stream, self.request_callback,
            no_keep_alive=self.no_keep_alive, xheaders=self.xheaders)