Well, you're not mocking all this up, but apparently it's working now. Ideally we would have unit tests for each new class we introduce. These tests are a little higher level and move towards integration tests for the new functionality, and are more focused towards testing the actions. Are there tests available that we can copy for the individual classes like the Iterator classes you've copied over? Something like https://github.com/eclipse/eclipse.jdt.ui/blob/master/org.eclipse.jdt.text.tests/src/org/eclipse/jdt/text/tests/JavaWordIteratorTest.java seems relevant.