EasyMock and methods with side effects

I really like EasyMock, but was disappointed to not see any explanation in the documention about how to simulate the modification of an argument of a method with side effects.

I thought that maybe I could write a custom argument matcher that modifies the argument (even if it seems weird to implement a side effect on the matches method of the IArgumentMatcher)

Actually, it was confirmed by this brilliant article about a Generic Custom Argument Matching in EasyMock