How test parent protected method calling

I am trying to test this kind of code :

class SMTPAppenderBase<ILoggingEvent>{

   protected void append(ILoggingEvent e){
      //someCode
      //someCode
      sendBuffer();
      //someCode
   }

   protected void sendBuffer(){
      //SomeCode
   }
}

---

class SMTPAppender extends SMTPAppenderBase<ILogging>{

   //someMethod
}

---

class CustomAppender extends SMTPAppender{

   protected void append(ILoggingEvent e){
      //someCode
      //someCode
      super.append(e)
      //someCode
   }
}

I need to test how many times super.append(e) is calling from CustomAppender. This must be done in @Test method.

How should I do this? I thought about :

• Mockito --> mock/spy. But it seems to be difficult with parent AND protected method.

• Anonym class into CustomAppender -->

  CustomAppender appender = new CustomAppender() {
  
          @Override
          protected void sendBuffer() {
              //my counter here
              super.sendBuffer();
          }
      };
  
  

Thank you for your help.