docs: private void writePointerLink(CmsResource res) throws CmsException {
  
          String resPath = getCms().getSitePath(res);
          String currentPropertyValue = getParamPropertyValue();
          boolean locked = true;
          CmsLock lock = getCms().getLock(res);
          if (lock.isUnlocked()) {
              // lock resource before operation
              getCms().lockResource(resPath);
              locked = false;
          }
          CmsFile file = getCms().readFile(res);
          file.setContents(currentPropertyValue.getBytes());
          checkLock(getCms().getSitePath(res));
          getCms().writeFile(file);
          if (!locked) {
              // unlock the resource
              getCms().unlockResource(resPath);
          }
      }