Warning after update to 2.0

public function onBeforeVendorListingDisplay(&$view, &$params) {

JFactory::getApplication()->triggerEvent('onBeforeVendorListingDisplay', array(&$this, &$trigger_params));

return call_user_func_array(array($this, $event), $args);

/** * Method to trigger events. * The method first generates the even from the argument array. Then it unsets the argument * since the argument has no bearing on the event handler. * If the method exists it is called and returns its return value. If it does not exist it * returns null. * * @param array &$args Arguments * * @return mixed Routine return value * * @since 11.1 */ public function update(&$args) { // First let's get the event from the argument array. Next we will unset the // event argument as it has no bearing on the method to handle the event. $event = $args['event']; unset($args['event']); /* * If the method to handle an event exists, call it and return its return * value. If it does not exist, return null. */ if (method_exists($this, $event)) { return call_user_func_array(array($this, $event), $args); } }