code: function (topLevelType, targetInst, nativeEvent, nativeEventTarget) {
  	    var events;
  	    var plugins = EventPluginRegistry.plugins;
  	    for (var i = 0; i < plugins.length; i++) {
  	      // Not every plugin in the ordering may be loaded at runtime.
  	      var possiblePlugin = plugins[i];
  	      if (possiblePlugin) {
  	        var extractedEvents = possiblePlugin.extractEvents(topLevelType, targetInst, nativeEvent, nativeEventTarget);
  	        if (extractedEvents) {
  	          events = accumulateInto(events, extractedEvents);
  	        }
  	      }
  	    }
  	    return events;
  	  }
docs: Allows registered plugins an opportunity to extract events from top-level
  native browser events.
  
  @return {*} An accumulation of synthetic events.
  @internal