code: @Override public int compareTo(Annotation that) {
      if (this == that) return 0;
      int byTimestamp = timestamp() < that.timestamp() ? -1 : timestamp() == that.timestamp() ? 0 : 1;
      if (byTimestamp != 0) return byTimestamp;
      return value().compareTo(that.value());
    }
docs: Compares by {@link #timestamp}, then {@link #value}.