How to handle appointments for multiple resources in the Flutter Calendar

bool _isJoseph = false;
bool _isStephen = false;
List<Appointment>? _appointments;
DataSource? _dataSource;
List<Appointment>? _josephAppointments, _stephenAppointments;
 
@override
void initState() {
  _dataSource = _getCalendarDataSource();
  super.initState();
}

SafeArea(
  child: Row(
    children: <Widget>[
      Switch(
        value: _isJoseph,
        onChanged: (value) {
          setState(() {
            if (value) {
              _updateJosephAppointments();
              _dataSource!.appointments!.addAll(_josephAppointments!);
              _dataSource!.notifyListeners(
                  CalendarDataSourceAction.reset, _josephAppointments!);
            } else {
              for (int i = 0; i < _josephAppointments!.length; i++) {
                _dataSource!.appointments!.remove(_josephAppointments![i]);
              }
              _josephAppointments!.clear();
              _dataSource!.notifyListeners(
                  CalendarDataSourceAction.reset, _josephAppointments!);
            }
            _isJoseph = value;
          });
        },
        activeTrackColor: Colors.lightGreenAccent,
        activeColor: Colors.green,
      ),
      Text('Dr.Joseph (Nephrologist)'),
    ],
  ),
),
 
void _updateJosephAppointments() {
  _josephAppointments = _josephAppointments ?? <Appointment>[];
  Appointment newAppointment = Appointment(
    startTime: DateTime.now(),
    endTime: DateTime.now().add(Duration(hours: 1)),
    subject: 'Interactive Live Workshop on Robotic Surgery in Gynecology',
    color: Colors.lightGreen,
  );
  Appointment newAppointment1 = Appointment(
    startTime: DateTime.now().add(Duration(days: -3, hours: 6)),
    endTime: DateTime.now().add(Duration(days: -3, hours: 7)),
    subject:
    'Billion Hearts Beating brings you Happy Heart Fest to celebrate World Heart Day',
    color: Colors.lightGreen,
  );
  Appointment newAppointment2 = Appointment(
    startTime: DateTime.now().add(Duration(days: -2, hours: 5)),
    endTime: DateTime.now().add(Duration(days: -2, hours: 6)),
    subject: 'Join Hands for Patient Safety',
    color: Colors.lightGreen,
  );
  Appointment newAppointment3 = Appointment(
    startTime: DateTime.now().add(Duration(days: -1, hours: 4)),
    endTime: DateTime.now().add(Duration(days: -1, hours: 5)),
    subject: 'Robotic GI Surgery International Congress',
    color: Colors.lightGreen,
  );
  Appointment newAppointment4 = Appointment(
    startTime: DateTime.now().add(Duration(days: 3, hours: 8)),
    endTime: DateTime.now().add(Duration(days: 3, hours: 9)),
    subject: 'World Continence Week - Free Check-up Camp for women',
    color: Colors.lightGreen,
  );
  _josephAppointments!.add(newAppointment);
  _josephAppointments!.add(newAppointment1);
  _josephAppointments!.add(newAppointment2);
  _josephAppointments!.add(newAppointment3);
  _josephAppointments!.add(newAppointment4);
}
 
void _updateStephenAppointments() {
  _stephenAppointments = _stephenAppointments ?? <Appointment>[];
  Appointment newAppointment5 = Appointment(
    startTime: DateTime.now(),
    endTime: DateTime.now().add(Duration(hours: 1)),
    subject: 'CME (Continuing Medical Education) Program',
    color: Colors.lightBlue,
  );
  Appointment newAppointment6 = Appointment(
    startTime: DateTime.now().add(Duration(days: 1, hours: 4)),
    endTime: DateTime.now().add(Duration(days: 1, hours: 5)),
    subject: '4th Clinical Nutrition Update',
    color: Colors.lightBlue,
  );
  Appointment newAppointment7 = Appointment(
    startTime: DateTime.now().add(Duration(days: 2, hours: 3)),
    endTime: DateTime.now().add(Duration(days: 2, hours: 4)),
    subject: 'National CME on Contemporary Developments in Transplants',
    color: Colors.lightBlue,
  );
  Appointment newAppointment8 = Appointment(
    startTime: DateTime.now().add(Duration(days: 3, hours: 6)),
    endTime: DateTime.now().add(Duration(days: 3, hours: 7)),
    subject: 'Oncological Robotic Surgery',
    color: Colors.lightBlue,
  );
  Appointment newAppointment9 = Appointment(
    startTime: DateTime.now().add(Duration(days: -1, hours: 6)),
    endTime: DateTime.now().add(Duration(days: -1, hours: 7)),
    subject: 'World Ostomy Day and Awareness Program',
    color: Colors.lightBlue,
  );
  _stephenAppointments!.add(newAppointment5);
  _stephenAppointments!.add(newAppointment6);
  _stephenAppointments!.add(newAppointment7);
  _stephenAppointments!.add(newAppointment8);
  _stephenAppointments!.add(newAppointment9);
}

Expanded(
    child: SfCalendar(
  view: CalendarView.week,
  dataSource: _dataSource,
))