docs: private String getPropertyFileName(CmsResource res) {
  
          StringBuffer ret = new StringBuffer();
  
          // path to the parent folder
          String parentFolder = CmsResource.getParentFolder(res.getRootPath());
          ret.append(parentFolder);
  
          // make sure ends with a slash
          if (!parentFolder.endsWith("/")) {
              ret.append("/");
          }
  
          // append name of the property folder
          ret.append(PROPERTY_DIR);
          ret.append("/");
  
          // if resource is a folder add the prefix "__"
          if (res.isFolder()) {
              ret.append(FOLDER_PREFIX);
          }
  
          // append the name of the resource
          ret.append(res.getName());
  
          return ret.toString();
      }