anchor.diff:  
                           UpdateCheckout(checkout);
   
  -                        if (CurrentCheckout.ready()) {
  +                        if (isReady(CurrentCheckout)) {
                               callback(null, null);
                           } else {
                               #if !SHOPIFY_MONO_UNIT_TEST
                                   UnityTimeout.Start(POLL_DELAY_SECONDS, () => {
  -                                    CheckoutPoll(callback);    
  +                                    PollTillReady(isReady, callback);
                                   });
                               #else
  -                                CheckoutPoll(callback);
  +                                PollTillReady(isReady, callback);
                               #endif
                           }
                       }
  
positive.code:             } catch(NoQueryException exception) {}
          }
  
          private void CheckoutPoll(Action<List<string>, string> callback) {
              if (CurrentCheckout.ready()) {
                  callback(null, null);
              } else {
                  QueryRootQuery query = new QueryRootQuery();
  
negative.code:             }
          }
  
          private void CheckoutPoll(Action<List<string>, string> callback) {
              PollTillReady(
                  checkout => {
                      return checkout.ready();
                  },
                  callback
              );
          }
  
          private void OnDeleteLineItem(string lineItemId) {
              DeletedLineItems.Add(lineItemId);
          }
  