Files with .class extension are hidden and ignored when used in a resources folder

I need write tests that use class files as test data so I put them in a `resources` source folder to have them copied to the output directory so that they are available to access through the classpath. That works for any other file, but eclipse would just filter out .class files they cannot be made visible even in Package or Project Explorer by tweaking filters.

I understand that might be by design and it should be the default behavior, but it would be useful to be able to customize the project so that they could be included if needed.