code: @SuppressWarnings("unchecked")
      public static MultiValueMap<String, String> getParamsFromQueryString(String queryString) {
          MultiValueMap queryParams = new LinkedMultiValueMap<>();
  
          if (StringUtils.isNotEmpty(queryString)) {
              String[] params = queryString.split("&");
              for (String param : params) {
                  String[] splitParam = param.split("=");
                  String paramName = splitParam[0];
                  String paramValue = splitParam[1];
  
                  queryParams.add(paramName, paramValue);
              }
          }
  
          return queryParams;
      }
docs: Returns a map with the extracted parameters from the specified query string. A multi value map is used
  since there can be several values for the same param.
  
  @param queryString the query string to extract the params from
  @return the param map