code: public TreeBuilder<T> convert(ContentConverter<T> converter, Path subpath,
              ResourceSelector<T> resourceSelector) {
          return convert(converter, PathUtil.subpathSelector(subpath), resourceSelector);
      }
docs: Convert data content for all resources matching the resource selector and within the sub path
  
  @param converter        content converter
  @param subpath          sub path
  @param resourceSelector resource selector
  
  @return builder