code: private void addMarkerAnnotation() {
  
      if (isLog(4)) {
        log("... adding marker annotation");
      }
      AnnotationVisitor av = cv.visitAnnotation(ANNOTATION_ALREADY_ENHANCED_MARKER, true);
      if (av != null) {
        av.visitEnd();
      }
    }
docs: Add the marker annotation so that we don't enhance the type query bean twice.