code: public String getResourceListAsParam() {
  
          String result = getParamResourcelist();
          if (CmsStringUtil.isEmptyOrWhitespaceOnly(result)) {
              result = getParamResource();
          }
          return result;
      }
docs: Returns the value of the resourcelist parameter in form of a String separated
  with {@link #DELIMITER_RESOURCES}, or the value of the  resource parameter if the
  first parameter is not provided (no multiple choice has been done.<p>
  
  This may be used for jsps as value for the parameter for resources {@link #PARAM_RESOURCELIST}.<p>
  
  @return the value of the resourcelist parameter or null, if the parameter is not provided