protected override void DoExecute(CodeActivityContext context)
        {
            var internalId = InternalId.Get(context);

            devlog.DebugFormat("Entered for '{0}'", internalId);
            var found = ExchangeRepository.ExchangeAppointmentByInternalId(internalId);

            try
            {
                ExchangeAppointment.Set(context, found.Value);
                devlog.DebugFormat("found '{0}'", found.Value);
            }
            catch (NullReferenceException)
            {
                ExchangeAppointment.Set(context, null);
                devlog.DebugFormat("found nothing");
            }
        }