public double getVarianceForTest() {
    double variance = 0;

    for (Member member : members.values()) {
      variance += variance(member.getTotalLoad(), member.getWeight(), getAverageLoad());
    }

    return variance;
  }
For testing only, calculate the total variance of the members
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/rebalance/model/PartitionedRegionLoadModel.java