http://developer.yahoo.com/yui/3/event/#eventsimulation
"""
Simulated events are browser-created events that, most of the time, behave exactly as user-initated events. Events bubble as they normally would and event objects are created with properties containing data about the event (sometimes these properties are browser-specific, so it's recommended that you make use of the browser-equalizing methods of Y.Event to retrieve the appropriate values for properties such as target, relatedTarget, and charCode. All event handlers are called synchronously at each event target throughout the event's lifetime. Events are simulated using the simulate() method on any Y.Node instance.
"""