String (@NotNull Project project, @NotNull Editor editor, @NotNull PsiFile file) { final PsiMember source = findSource(editor, file); if (source instanceof PsiClass) { return GroovyBundle.message("no.super.classes.found"); } else if (source instanceof PsiMethod || source instanceof GrField) { return GroovyBundle.message("no.super.method.found"); } else { throw new IncorrectOperationException("incorrect element is found: " + (source == null ? "null" : source.getClass().getCanonicalName())); } }