public static List<User> getManagerList(List<User> userList, boolean includeAdder) {
    List<User> list = new ArrayList<User>();

    for (User user : userList) if (user.isManager()) list.add(user);

    if (includeAdder) list.add(User.newInstance(User.MEMBER_ID_NEW_MANAGER, "", ""));

    return list;
  }
  public static List<User> getNormalMemberList(List<User> userList, boolean includeAdder) {
    List<User> list = new ArrayList<User>();

    for (User user : userList) list.add(user);

    if (includeAdder) list.add(User.newInstance(User.MEMBER_ID_INVITE_KAKAO, "", ""));

    return list;
  }