Testing a Custom Language plugin

Hi again, this may be related to my problems with AstWrapperPsiElement

How should one test a Custom Language plugin?  I would like to set up a JUnit suite, and I have been looking at the Groovy plugin test code.

However, this code seems to rely on classes that are not in my IDEA SDK.  For example,  IdeaTestApplication, ProjectManagerEx, PersistentFS, JavaPsiFacadeEx and IdeaLogger.

Thanks again
Peter