I don't use JUnit, but I have two bodies of imported source code from different libraries and both use JUnit; however, they seem to be using a different version. 

For example, one imports things like `junit.runner...` and the other has `org.junit.runners...`. 

I read a little bit of the JUnit documentation and it appears that they do not follow a strict backward compatibility principle and different versions apparently have different features and require different code, so there would appear to be no simple way to "upgrade" one of my libraries to the latest version.

How do I deal with this incompatibility? (other than just throw out all the tests which I am half inclined to do)