docs: def _map_relation(c, language='any'):
      """
      Map related concept or collection, leaving out the relations.
  
      :param c: the concept or collection to map
      :param string language: Language to render the relation's label in
      :rtype: :class:`dict`
      """
      label = c.label(language)
      return {
          'id': c.id,
          'type': c.type,
          'uri': c.uri,
          'label': label.label if label else None
      }