docs: @Override
    public long rankLong(int x) {
      long size = 0;
      short xhigh = highbits(x);
      for (int i = 0; i < this.highLowContainer.size(); i++) {
        short key = this.highLowContainer.getKeyAtIndex(i);
        int comparison = Util.compareUnsigned(key, xhigh);
        if (comparison < 0) {
          size += this.highLowContainer.getCardinality(i);
        } else if(comparison == 0) {
          return size + this.highLowContainer.getContainerAtIndex(i).rank(lowbits(x));
        }
      }
      return size;
    }