def __pack_message(operation, data):
request_id = random.randint(-<NUM_LIT:2> ** <NUM_LIT> - <NUM_LIT:1>, <NUM_LIT:2> ** <NUM_LIT>)<EOL>message = struct.pack("<STR_LIT>", <NUM_LIT:16> + len(data))<EOL>message += struct.pack("<STR_LIT>", request_id)<EOL>message += __ZERO  <EOL>message += struct.pack("<STR_LIT>", operation)<EOL>return (request_id, message + data)<EOL>
Takes message data and adds a message header based on the operation.

    Returns the resultant message string.