code: public B camundaTaskListenerClass(String eventName, String fullQualifiedClassName) {
      CamundaTaskListener executionListener = createInstance(CamundaTaskListener.class);
      executionListener.setCamundaEvent(eventName);
      executionListener.setCamundaClass(fullQualifiedClassName);
  
      addExtensionElement(executionListener);
  
      return myself;
    }
docs: Add a class based task listener with specified event name
  
  @param eventName - event names to listen to
  @param fullQualifiedClassName - a string representing a class
  @return the builder object