code: private <T> void storeInMap(MultiValueMap<T> map, T key, String[] values) {
          try {
              map.set(key, values);
          } catch (Exception e) {
              throw new IllegalArgumentException(e);
          }
      }
docs: This method covers the totally bogus Exception that is thrown by
  MultiValueMap.set(), and wraps it in an IllegalArgumentException, which
  is more appropriate.
  @param <T>