private void SavePayPalInvoice(Guid reconnectToOurBuyer,
         PayPal.Api.Payments.Payment createdInvoice)
 {
     // we will retrieve this so that PayPal can apply,
     // i.e., "execute", the invoice that the customer
     // has approved.  For this example, we are using
     // Entity Framework 6.0.2 with Code First.
     TinyInvoice invoiceToSave              = new TinyInvoice();
     invoiceToSave.ReconnectToOurBuyer      = reconnectToOurBuyer;
     invoiceToSave.PayPalPayment_Identifier = createdInvoice.id;
     using (ArgumentsPlus.Controllers.ArgumentPlusContext
            argumentsPlusDb
            = new ArgumentPlusContext())
     {
         argumentsPlusDb.TinyInvoices.Add(invoiceToSave);
         argumentsPlusDb.SaveChanges();
     }
 }
 private PayPal.Api.Payments.Payment GetSavedPayPalInvoice(string id)
 {
     Guid savedInvoiceKey = new Guid(); // will be all zeros
     try
     {
         savedInvoiceKey  = new Guid(id);
     }
     catch (Exception)    // could happen; probability low
     {
         // todo for now ignore ==> TIMTOWTDI
     }
     //
     PayPal.Api.Payments.Payment createdInvoice
         = new PayPal.Api.Payments.Payment(); // scope outside using
     // ................................
     using (ArgumentsPlus.Controllers.ArgumentPlusContext
      argumentsPlusDb
      = new ArgumentPlusContext())
     {
         var approvedPayPalPayment
             = argumentsPlusDb.TinyInvoices// define the query
              .Where(guid => guid.ReconnectToOurBuyer == savedInvoiceKey);
         var getOnePayPalPendingPayment = approvedPayPalPayment.ToList();
                   // .ToList() will force the query to hit the database
         Int32 numberOfInvoices = getOnePayPalPendingPayment.Count;
                                  // should be ZERO or ONE
         if (numberOfInvoices == 1)
         {
             createdInvoice.id
                 = getOnePayPalPendingPayment[0].PayPalPayment_Identifier;
         } // if (numberOfInvoices == 1)
         else // should ALWAYS be ONE !!!!!!!!!
         {
             throw new NotImplementedException();  // todo "well, this is embarrassing"
         }
     }
     return createdInvoice;
 }