Event()

As you see it is part of the javascript functions which are callable from the plugin.
In that function you should work with the incomeing events.
So if the plugin get an event, like click on one of your model, it will
try to call this function with a string parameter which will tell what is the event.
The use and the initalization procedure is already writed in the
"Just few word about initalization" named part of the documentation.