@Override
  public int compareTo(InternalPartitionDetails other) {
    // memberId is InternalDistributedMember which implements Comparable
    return distributedMember.compareTo(other.getDistributedMember());
  }
hashCode is defined for this class to make sure that the before details and after details for
RebalanceResults are in the same order. This makes debugging printouts easier, and it also
removes discrepancies due to rounding errors when calculating the stddev in tests.
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/PartitionMemberInfoImpl.java