code: function (data) {
  		if (mockIndexedDBTestFlags.canSave === true) {
  			mockIndexedDBItems.push(data);
  			mockIndexedDB_storeAddTimer = setTimeout(function () {
  				mockIndexedDBTransaction.callCompleteHandler();
  				mockIndexedDB_saveSuccess = true;
  			}, 20);
  		}
  		else {
  			mockIndexedDB_storeAddTimer = setTimeout(function () {
  				mockIndexedDBTransaction.callErrorHandler();
  				mockIndexedDB_saveFail = true;
  			}, 20);
  		}
  
  		return mockIndexedDBTransaction;
  	}
docs: add returns a different txn than delete does. in indexedDB, the listeners are attached to the txn that returned the store.