@Override
  public int compareTo(final @NotNull FileChunkKey<OwnerType> o) {
    if (owner != o.owner) {
      return owner.hashCode() - o.owner.hashCode();
    }
    return offset == o.offset ? 0 : offset - o.offset < 0 ? -1 : 1;
  }
@Override
  public int compareTo(final @NotNull FileChunkKey<OwnerType> o)