docs: protected void appendCopiesUntil(RoaringArray sourceArray, short stoppingKey) {
      int stopKey = Util.toIntUnsigned(stoppingKey);
      for (int i = 0; i < sourceArray.size; ++i) {
        if (Util.toIntUnsigned(sourceArray.keys[i]) >= stopKey) {
          break;
        }
        extendArray(1);
        this.keys[this.size] = sourceArray.keys[i];
        this.values[this.size] = sourceArray.values[i].clone();
        this.size++;
      }
    }