listen method
Starts listening to the underlying stream.
Returns a Future that will complete when the connection is closed or when it has an error. This is the same as done.
listen may only be called once.
Implementation
Future listen() {
_channel.stream.listen(_handleRequest, onError: (error, stackTrace) {
_done.completeError(error, stackTrace);
_channel.sink.close();
}, onDone: () {
if (!_done.isCompleted) _done.complete();
});
return done;
}