The "Unused Declaration" code inspection is very useful for finding redundant code that is no longer used by your application and can be safely removed. The inspection fails, however, if there is a Unit test that exercises a method that is otherwise not used anywhere.
This makes the "Unused Declaration" inspection almost useless if you have a comprehensive test suite.
It would be great if the user could exclude the "tests" source tree from this inspection. So that if a method is only ever used in a Unit test the inspection will tell you it is unused.