private void Button_ClickAccept(object sender, RoutedEventArgs e)
        {
            if (ToMe.SelectedItem != null)
            {
                GetterRequests g = ToMe.SelectedItem as GetterRequests;
                us = rep.ChangeStatusToAccept;
                us.Invoke(g);
                MessageBox.Show("You accepted this request");
            }

            else
            {
                MessageBox.Show("Please, select a request", "Oops", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }
 private void Button_ClickDecline(object sender, RoutedEventArgs e)
 {
     if (ToMe.SelectedItem != null)
     {
         GetterRequests g = ToMe.SelectedItem as GetterRequests;
         us = rep.ChangeStatusToDecline;
         us.Invoke(g);
         var RequestsToMe = rep.ToGetRequestsToMe(ThisUser);
         ToMe.ItemsSource = RequestsToMe;
         MessageBox.Show("You declined this request");
     }
     else
     {
         MessageBox.Show("Please, select a request", "Oops", MessageBoxButton.OK, MessageBoxImage.Error);
     }
 }