Sorts the internal list of listeners for the given event by priority.
string $eventName The name of the event.:
private function sortListeners($eventName) {
$this->sorted[$eventName] = array();
if (isset($this->listeners[$eventName])) {
krsort($this->listeners[$eventName]);
$this->sorted[$eventName] = call_user_func_array('array_merge', $this->listeners[$eventName]);
}
}