code: protected List<ExtensionComponent<T>> sort(List<ExtensionComponent<T>> r) {
          r = new ArrayList<>(r);
          Collections.sort(r);
          return r;
      }
docs: If the {@link ExtensionList} implementation requires sorting extensions,
  override this method to do so.
  
  <p>
  The implementation should copy a list, do a sort, and return the new instance.