a reference to the corresponding core Core
the event namespace string (e.g. "foo" for "foo.tap")
originalEvent : the original user input device event object
position : indicates the model position of the event
renderedPosition : indicates the rendered position of the event
indicates the element or core that first caused the event
Unix epoch time of event in milliseconds
the event type string (e.g. "tap")
http://js.cytoscape.org/#events/event-object