code: private void addAnnotation(PsiElementFactory elementFactory, JavaCodeStyleManager styleManager) {
  
      boolean annotated = AnnotationUtil.isAnnotated(psiClass, ANNOTATION_PACKAGE+"."+ANNOTATION_NAME, false);
  
      if (!annotated) {
        styleManager.shortenClassReferences(psiClass.getModifierList().addAnnotation(
            ANNOTATION_NAME));
      }
    }
docs: Add the @Parcelable annotation if not already annotated