docs: ArrayTagSet addAll(Tag[] ts, int tsLength) {
      if (tsLength == 0) {
        return this;
      } else if (length == 0) {
        Arrays.sort(ts, 0, tsLength, TAG_COMPARATOR);
        int len = dedup(ts, 0, ts, 0, tsLength);
        return new ArrayTagSet(toStringArray(ts, len));
      } else {
        String[] newTags = new String[(length + tsLength) * 2];
        Arrays.sort(ts, 0, tsLength, TAG_COMPARATOR);
        int newLength = merge(newTags, tags, length, ts, tsLength);
        return new ArrayTagSet(newTags, newLength);
      }
    }