Test::Kit allows you to create a single module in your project which gives you access to all of the testing functions you want.
Its primary goal is to reduce boilerplate code that is currently littering the top of all your test files.
It also allows your testing to be more consistent; for example it becomes a trivial change to include Test::FailWarnings in all of your tests, and there is no danger that you forget to include it in a new test.