code: List<MemberState> getReserveMemberStates(Comparator<MemberState> comparator) {
      List<MemberState> reserveMembers = new ArrayList<>(getReserveMemberStates());
      Collections.sort(reserveMembers, comparator);
      return reserveMembers;
    }
docs: Returns a list of reserve members.
  
  @param comparator A comparator with which to sort the members list.
  @return The sorted members list.