code: void load(ReferenceableInstance i) throws RepositoryException {
          int pos = idPosMap.get(i.getId());
          loadFields(pos, i);
  
          for (HierarchicalTypeStore s : superTypeStores) {
              s.load(i);
          }
      }
docs: - copy over the immediate attribute values from the respective IAttributeStore
  - call load on each SuperType.
  @param i
  @throws RepositoryException