@Override
    public void visitClass(@NotNull PsiClass aClass) {
      if (aClass.isInterface() || aClass.isAnnotationType() || aClass.isEnum()) {
        return;
      }
      if (aClass instanceof PsiTypeParameter) {
        return;
      }
      if (!aClass.hasModifierProperty(PsiModifier.ABSTRACT)) {
        return;
      }
      if (!InheritanceUtil.hasOneInheritor(aClass)) {
        return;
      }
      registerClassError(aClass);
    }
@Override
    public void visitClass(@NotNull PsiClass aClass)