Create a channel object using the token returned by the createChannel() call on the server.
Open a socket on this channel. open() returns a goog.appengine.Socket object. You can set the callback properties directly on the returned socket object or set them using an optional object handler with the following properties: onopen, onmessage, onerror, onclose . If the token specified during channel creation is invalid or expired then the onerror and onclose callbacks will be called. The code field for the error object will be 401 (Unauthorized) and the description field will be 'Invalid+token.' or 'Token+timed+out.' respectively. The onerror callback is also called asynchronously whenever the token for the channel expires. An onerror call is always followed by an onclose call and the channel object will have to be recreated after this event.