code: function mapHierarchicalCodelist (e) {
      // TODO add levels
      var hcl = mapMaintainableArtefact(e);
  
      var hierarchies = _getChildrenNS(e, 'Hierarchy');
      if (hierarchies.length === 0) return hcl;
  
      hcl.items = hierarchies.map(function (h) {
        return mapItemScheme(h);
      });
  
      return hcl;
    }
docs: ------------------------------------------------------------------------------