@Override
    public void visitClass(@NotNull PsiClass aClass) {
      // no call to super, so it doesn't drill down
      if (aClass.isInterface() || aClass.isEnum() || aClass.isAnnotationType()) {
        return;
      }
      if (aClass instanceof PsiTypeParameter || aClass instanceof PsiAnonymousClass) {
        return;
      }
      final PsiMethod[] constructors = aClass.getConstructors();
      if (constructors.length > 0) {
        return;
      }
      registerClassError(aClass);
    }
@Override
    public void visitClass(@NotNull PsiClass aClass)