This calls a procedure with the given arguments and/or argumentsKeywords
with the given options. The WAMP router will either respond with one or
more results or the caller may cancel the call by calling cancelCompleter.complete().
Sends a goodbye message and closes the transport after a given timeout.
If no timeout is set, the client waits for the server to close the transport forever.
This subscribes the session to a topic. The subscriber may pass options
while subscribing. The resulting events are passed to the Subscribed.eventStream.
The subscriber should therefore subscribe to that stream to receive the events.