The Callback hierarchy is an incomplete mess

[Noblebrown]

The hierarchy starting with the interface Callback is obviously incomplete and non-functional. AbstractAsyncCallback works with a mutable static boolean to determine if it should run the child method of processMe(), and when it does, it sets the boolean and sleeps for one second.

Not only is the static variable usage in a class designed for multithreading horrific, but the whole thing doesn't even do much of anything. I'm guessing that this was test code that was never completed and left in place. This hierarchy should be revised. I'd recommend flattening it and allowing for easy extension to add desired behavior.