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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 next(self):
 """Request next data container. This function call is blocking. Returns ------- data : dict The data for this train, keyed by source name. meta : dict The metadata for this train, keyed by source name. This dictionary is populated for protocol version 1.0 and 2.2. For other protocol versions, metadata information is available in `data` dict. Raises ------ TimeoutError If timeout is reached before receiving data. """

        if self._pattern == zmq.REQ and not self._recv_ready:
            self._socket.send(b'next')
            self._recv_ready = True
        try:
            msg = self._socket.recv_multipart(copy=False)
        except zmq.error.Again:
            raise TimeoutError(
                'No data received from {} in the last {} ms'.format(
                    self._socket.getsockopt_string(zmq.LAST_ENDPOINT),
                    self._socket.getsockopt(zmq.RCVTIMEO)))
        self._recv_ready = False
        return self._deserialize(msg)