docs: String getFolderFilter() {
  
          String result = "";
          List<String> parentFolderVals = Lists.newArrayList();
          if (!m_config.getFolders().isEmpty()) {
              for (String value : m_config.getFolders()) {
                  parentFolderVals.add("\"" + value + "\"");
              }
          }
          if (parentFolderVals.isEmpty()) {
              result = "fq=parent-folders:(\"/\")";
          } else {
              result = "fq=parent-folders:(" + CmsStringUtil.listAsString(parentFolderVals, " OR ") + ")";
          }
          return result;
      }