Do you want a class to never EVER be deleted?

Just add in the comments that it's "temporary".

You forgot to add a TODO: to it.

TODO : remove this

*things just become immortal*

Write a script that generates hundreds of unit tests for methods within that class, give the tests random names, and spread them randomly throughout all the test suites.

If you use a language which allows dynamic metaprogramming like PHP you could also spread cryptic things like [strrev("emaNssalC", "m"."ethodN"."ame"](); all throughout the codebase, so it fails if the class/method doesn't exist and is extremely hard to search for.

@bittersweet let's just wait for the rest of the code to spontaneously become dependent on that single class.