Neffos supports unlimited number of rooms under a connected namespace.

1. Each connection connected to a namespace can join to one or more rooms.
2. Rooms are dynamic.
3. `Server#Broadcast(Message {Namespace: ..., Room: ...})` sends data to all clients connected to a specific `Namespace:Room`.
4. Client and server can ask remote side to join to a room, get notified by `OnRoomJoin` and `OnRoomJoined`.
5. Client and server can ask remote side to leave from a room, get notified by `OnRoomLeave` and `OnRoomLeft`.
6. Client and server can disallow remote request for room join through their `OnRoomJoin -> return err != nil`. 
7. Client and server can disallow remote request for room leave through their `OnRoomLeave -> return err != nil`.

```go
// blocks until join in both sides.
room, err := nsConn.JoinRoom(ctx, "room")
```

```go
room.Emit("event", body)
// room.NSConn.Conn.Write(neffos.Message{
//     Namespace: "namespace",
//     Room:      "room",
//     Event:     "event",
//     Body:      body,
// })
```

```go
room.Leave(ctx)
```