Broadcast to local instance only when using the redis-adapter

[sleimanx2]

it's possible to add the local flag when emitting to a room

 // sending to all clients on this node (when using multiple nodes)
 io.to(channel).local
     .emit(message.event, channel, message.data)

however, when broadcasting from a socket instance it's not possible to add a local flag is there any way to achieve the same behavior?

// this wont work
socket.broadcast.to(channel).local
      .emit(message.event, channel, message.data);

thank you

[darrachequesne]

Closed by #3219