I also noticed that Wicket has some pretty good mocks, in particular their ServletContext. They are APL 2.0. But according to http://www.fsf.org/licensing/licenses/index_html#GPLCompatibleLicenses
it is not compatible with GPL 2.1 (I have no idea if this applies to LGPL).
Please note that the APL 2 license is not compatible with GPL version 2, because it has some requirements that are not in the older version. These include certain patent termination and indemnification provisions.
So does anyone know if I can take a class from Wicket?