public void AppointmentDateChangedByOwner(AppointmentDTO appointmentDTO) { var appointmentNotification = _iAppointmentBus.UpdateAppointmentDateChangedByInitiator(appointmentDTO); var send = JsonConvert.SerializeObject(appointmentNotification); _clients.FirstOrDefault(r => ((AppointmentWebSocketHandler)r)._userId == appointmentDTO.AdvertismentOwnerId).Send(send); }