Byteman - use it when Mockito can't help

Byteman is a really cool stuff with which you could simulate JVM or OS behavior hardly possible to mock using mocking library (like Mockito). Read the full exaple (really short with no fluff) here: http://theholyjava.wordpress.com/2012/02/25/cool-tools-fault-injection-into-unit-tests-with-jboss-byteman-easier-testing-of-error-handling/