code: function(transaction, event) {
          var success = !!event.status,
              funcName = success ? 'success' : 'failure',
              callback, options, result;
          
          if (transaction && transaction.callback) {
              callback = transaction.callback;
              options  = transaction.callbackOptions;
              result   = typeof event.result !== 'undefined' ? event.result : event.data;
  
              if (Ext.isFunction(callback)) {
                  callback(result, event, success, options);
              }
              else {
                  Ext.callback(callback[funcName], callback.scope, [result, event, success, options]);
                  Ext.callback(callback.callback,  callback.scope, [result, event, success, options]);
              }
          }
      }
docs: Run any callbacks related to the transaction.
  
  @param {Ext.direct.Transaction} transaction The transaction
  @param {Ext.direct.Event} event The event
  
  @private