@Override
    protected ID<?, ?> readStubIndexKey(@NotNull DataInput input, FileLocalStringEnumerator enumerator) throws IOException {
      int idx = DataInputOutputUtil.readINT(input);
      String name = enumerator.valueOf(idx);
      if (name == null) {
        throw new IOException("corrupted data: no value for idx = " + idx + " in local enumerator");
      }
      return ID.findByName(name);
    }
@Override
    protected ID<?, ?> readStubIndexKey(@NotNull DataInput input, FileLocalStringEnumerator enumerator)