@Override
  public int compareTo(CostBenefitInfo that) {
    int compareToVal = costBenefitRatio.compareTo(that.costBenefitRatio);
    if (compareToVal != 0) {
      return compareToVal;
    }
    return Integer.compare(that.benefit, benefit);
  }
CostBenefitInfo Stores cost benefit information for a potential candidate to be compacted
ambry-store/src/main/java/com/github/ambry/store/CostBenefitInfo.java