@Override
  public int compareTo(Member other) {
    // memberId is InternalDistributedMember which implements Comparable
    return memberId.compareTo(other.memberId);
  }
@param sourceMember the member we will be moving this bucket off of
@param checkZone true if we should not put two copies of a bucket on two nodes with the same
       IP address.
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/rebalance/model/Member.java