void () { final PsiFile file = myFixture.addFileToProject("empty.properties", ""); final ResourceBundleImpl bundle = new ResourceBundleImpl((PropertiesFile)file); bundle.invalidate(); ResourceBundleFileStructureViewElement myElement = new ResourceBundleFileStructureViewElement(bundle, () -> true); Assert.assertNull("Should return null on an invalidated resource bundle", myElement.getFiles()); }