Create a new flow to handle the flow of messages in the engine.io session.
Create a new flow to handle the flow of messages in the engine.io session.
It may seem odd that the flow produces a Seq[EngineIOMessage]. The reason it does this is because socket.io
binary events get encoded into multiple EngineIOMessage's. By producing messages in Seq's, we allow them to
be sent as one payload back to the client, otherwise they would usually be split.
The first request for this session.
The session id.
A handler for engine.io sessions.