const MsgType = {                // related payload classes
    // commands
    ROOM_ACTION: 'ROOM_ACTION', /** @link RoomActionCommand */ // actions: join, leave, modify          | IN 3x
    CHAT_MESSAGE: 'CHAT_MESSAGE', /** @link ChatMessageCommand */ // just chat message, also an update  | IN/OUT 1x
    MORE_MESSAGES: 'MORE_MESSAGES', /** @link MoreMessagesCommand */ //                                 | IN/OUT 1x

    // errors
    ERR: 'ERR', /** @link Err */    //                                                                  | OUT

    // listings
    ROOMS: 'ROOMS', /** @link RoomsListing */ //                                                        | OUT
    USERS: 'USERS', /** @link UsersListing */ //                                                        | OUT
    MESSAGES: 'MESSAGES', /** @link MessagesListing */ //                                               | OUT

    // updates
    ROOM_UPDATE: 'ROOM_UPDATE', /** @link RoomUpdate */ // actions: closed, opened, updated             | OUT
    USER_UPDATE: 'USER_UPDATE', /** @link UserUpdate */ // actions joined, left                         | OUT

    // system
    ACK: 'ACK',                            // ack has no payload, cause it's like ACK you know          | OUT
    AUTH: 'AUTH', /** @link AuthMessage */ //                                                           | IN 1x
    DISCONNECT: 'DISCONNECT'            /** @link DisconnectMessage */ //                               | OUT
}