@Override
  public int compareAdditionalData(MemberData o) {
    GMSMemberData his = (GMSMemberData) o;
    int result = 0;
    if (uuidMSBs != 0 && his.uuidMSBs != 0) {
      if (uuidMSBs < his.uuidMSBs) {
        result = -1;
      } else if (his.uuidMSBs < uuidMSBs) {
        result = 1;
      } else if (uuidLSBs < his.uuidLSBs) {
        result = -1;
      } else if (his.uuidLSBs < uuidLSBs) {
        result = 1;
      }
    }
    return result;
  }
return the jgroups logical address for this member, if it's been established
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/GMSMemberData.java