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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 unpack(cls, msg, client, server, request_id):
 """Parse message and return an `OpInsert`. Takes the client message as bytes, the client and server socket objects, and the client request id. """

        flags, = _UNPACK_INT(msg[:4])
        namespace, pos = _get_c_string(msg, 4)
        docs = bson.decode_all(msg[pos:], CODEC_OPTIONS)
        return cls(*docs, namespace=namespace, flags=flags, _client=client,
                   request_id=request_id, _server=server)