docs: ArrayTagSet addAll(String[] ts) {
      if (ts.length % 2 != 0) {
        throw new IllegalArgumentException("array length must be even, (length=" + ts.length + ")");
      }
  
      if (ts.length == 0) {
        return this;
      } else {
        int tsLength = ts.length / 2;
        Tag[] newTags = new Tag[tsLength];
        for (int i = 0; i < tsLength; ++i) {
          final int j = i * 2;
          newTags[i] = new BasicTag(ts[j], ts[j + 1]);
        }
        return addAll(newTags, tsLength);
      }
    }