Not sure whether we need those. I currently have a simple/lightweight POJO class in mind (i.e. not a component in the Plexus sense) that just has some constructors for initialization and that's it. The dispose() is intended to release resources like file handles on archives. However, it's not fully thought up (at least on my side ).
To further illustrate the intended usage:
Asserter asserter = new Asserter();
asserter.setCurrentDirectory( basedir );
runHookScript( ..., asserter );
asserter.assertFile( "target/foo-1.0.jar" );
asserter.setCurrentDirectory( "target/exploded" );
asserter.assertFile( "WEB-INF/lib/bar-1.0.jar" );