This is part of websocket crate that is independent from hyper.
It contains code for processing WebSocket streams,
(after HTTP upgrade already happened)
WebSocket message definition, some error type.
For now it still optionally depends on futures 0.1 and tokio-io 0.1, but that's going to
be extracted to a separate crate, if rust-websocket's depelopment continues.
Note that there is no normal example of usage so far. See usual websocket crate or
alternative like tungstenite.