code: function (event, delegateId, wrapTarget, container) {
              this.$assert(286, this.__delegateMapping);
              var eventWrapper = this.__wrapEvent(event, wrapTarget), result;
              var callback = this.__delegateMapping[delegateId];
              if (callback) {
                  result = callback.call(eventWrapper);
              }
              eventWrapper.$dispose();
              return result;
          }
docs: Entry point for event that were not delegated
  @param {HTMLEvent} event HTML Event
  @param {String} delegateId Id of the delegated callback
  @param {Boolean} wrapTarget, if true, wrap target into DomEventWrapper
  @param {HTMLElement} container HTML Element on which the listener is attached
  @return {Object} Return value of the callback