public override IEnumerable<IOccurrence> ConvertDraggedData(object data)
        {
            if (DataObjectHelper.GetDataPresent(data, typeof(Employee), false))
            {
                var employee = ((IEnumerable)DataObjectHelper.GetData(data, typeof(Employee), true)).Cast<Employee>().First() as Employee;

                if (employee != null)
                {
                    var appointment = new SupportMeetingAppointment { IsDraggedFromListBox = true };
                    appointment.Attendees.Add(employee);
                    return new List<SupportMeetingAppointment>() { appointment };
                }
            }

            return base.ConvertDraggedData(data);
        }
 public override IAppointment Copy()
 {
     var newAppointment = new SupportMeetingAppointment();
     newAppointment.CopyFrom(this);
     return newAppointment;
 }