Interface for anyone who wants to register to receive TestEvent
objects from a given test run.
By the way, you probably don't care about this interface, because there's
a nifty way to write custom event listeners that are hooked into the
XML document with the same kind of extensibility that you get from the
TestNode, and it includes cool stuff like filtering of events.
Basicall, if you are writing a program to load and execute tests and you
want highly interactive access to the event sink, use the typical Java Event
model of TestEventMgr.addTestEventListener() and support this interface.
When you want to use the built-in extensibility of LISA to create and use a
test event output mechanism that you can define within the test case itself,
then do ReportGenerator.