void (@NotNull final CodeInsightTestFixture fixture) { final ModuleRootManager manager = ModuleRootManager.getInstance(fixture.getModule()); final ModifiableRootModel model = manager.getModifiableModel(); final VirtualFile srcToMark = fixture.getTempDirFixture().getFile("test_with_src/foo/src"); assert srcToMark != null; model.addContentEntry(srcToMark); model.commit(); }