Classloader which instruments loaded classes for example to remove final modifiers.
The idea is that you use custom classloader as a system classloader.
To do it you should set java.system.class.loader property like this:
    -Djava.system.class.loader=org.definilizer.ClassLoaderForTesting

It may be useful if for example some classes cannot be changed is used in current code.
Without final modifiers it becomes possible to stub these classes and write unit test
for the code you work on. See org.definilizer.SingletonRemoving_Test for example.

This is source code for this post http://codingmatters.blogspot.com/2008/09/getting-rid-of-dependcies-part-2.html.