code: protected Map<String, Map<Integer, Set<String>>> createUpdateList() {
      Map<String, Map<Integer, Set<String>>> updateList = new HashMap<>();
      updateList.put(UPDATE_TYPE_OFFSET, new HashMap<>());
      updateList.put(UPDATE_TYPE_POSITION, new HashMap<>());
      updateList.put(UPDATE_TYPE_LOCAL_REF_POSITION_START, new HashMap<>());
      updateList.put(UPDATE_TYPE_LOCAL_REF_POSITION_END, new HashMap<>());
      updateList.put(UPDATE_TYPE_LOCAL_REF_OFFSET_START, new HashMap<>());
      updateList.put(UPDATE_TYPE_LOCAL_REF_OFFSET_END, new HashMap<>());
      updateList.put(UPDATE_TYPE_VARIABLE, new HashMap<>());
      return updateList;
    }
docs: Creates the update list.
  
  @return the map