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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 _read_message(self):
 """ Reads a message from the socket and converts it to a message. """

        # first 4 bytes is Big-Endian payload length
        payload_info = self._read_bytes_from_socket(4)
        read_len = unpack(">I", payload_info)[0]

        # now read the payload
        payload = self._read_bytes_from_socket(read_len)

        # pylint: disable=no-member
        message = cast_channel_pb2.CastMessage()
        message.ParseFromString(payload)

        return message