code: function mapItemScheme (e) {
        var itemName = {
          'CategoryScheme': 'Category',
          'Hierarchy': 'HierarchicalCode',
          'Codelist': 'Code',
          'ConceptScheme': 'Concept',
          'AgencyScheme': 'Agency'
        }[e.localName];
  
        var itemScheme = mapMaintainableArtefact(e);
        itemScheme.isPartial = toBoolean(getAttrValue(e, 'isPartial'));
      itemScheme.leveled = toBoolean(getAttrValue(e, 'leveled')); // Hierarchy
  
      var itemURN = [
      'urn:sdmx:org.sdmx.infomodel',
      '.', itemScheme.package,
      '', itemName,
      '=', itemScheme.agencyID,
      ':', itemScheme.id,
      '(', itemScheme.version, ')'
      ].join('');
  
      function mapItems (node, hierarchy) {
        var items = _getChildrenNS(node, itemName);
        if (items.length === 0) return undefined;
  
        function mapItem (e) {
          var item = mapVersionableArtefact(e); // HierarchicalCode = versionable
          item.agencyID = itemScheme.agencyID;
          item.maintainableParentID = itemScheme.id;
          item.maintainableParentVersion = itemScheme.version;
  
          if (item.urn === undefined) {
            item.urn = itemURN + hierarchy + '.' + item.id;
          }
  
          item.parent = mapLocalReference(_getFirstChildNS(e, 'parent'));
          item.items = mapItems(e, hierarchy + '.' + item.id);
  
          if (e.localName === 'Concept') {
            item.isoConceptReference = mapISOConceptReference(_getFirstChildNS(e, 'ISOConceptReference'));
            item.coreRepresentation = mapRepresentation(_getFirstChildNS(e, 'CoreRepresentation'));
          }
  
          if (e.localName === 'HierarchicalCode') {
            item.code = mapReference(_getFirstChildNS(e, 'Code'), 'code', 'code');
          }
  
          return item;
        }
  
        return items.map(mapItem);
      }
  
      itemScheme.items = mapItems(e, '');
  
      return itemScheme;
    }
docs: ------------------------------------------------------------------------------ Functions for mapping item scheme like artefacts