PHPDaemon\Core\CallbackWrapper::addToArray PHP Method

    public static function addToArray(&$arr, $cb)
    {
        if ($arr === null) {
            $arr = [];
        }
        $e = static::extractCb($cb);
        foreach ($arr as $item) {
            if (static::extractCb($item) === $e) {
                return false;
            }
        }
        $arr[] = $cb;
        return true;
    }

 /**
  * Bind event or events
  * @param string|array $event Event name
  * @param callable     $cb    Callback
  * @return this
  */
 public function bind($event, $cb)
 {
     if ($cb !== null) {
         $cb = CallbackWrapper::wrap($cb);
     }
     is_array($event) or $event = [$event];
     foreach ($event as $e) {
         CallbackWrapper::addToArray($this->eventHandlers[$e], $cb);
     }
     return $this;
 }