The root event class for all cache events. Each subclasses of this class
classifies a particular type of cache event.
author: Chris Miller author: Date: 20-May-2003 author: Time: 15:25:02
Creates a cache event object that came from the specified origin.
Parameters: origin - A string that indicates where this event was fired from.This value is optional; null can be passed in if anorigin is not required.
Retrieves the origin of this event, if one was specified. This is most
useful when an event handler causes another event to fire - by checking
the origin the handler is able to prevent recursive events being
fired.