Nette\Forms\Container::extensionMethod PHP Метод

    public static function extensionMethod($name, $callback = NULL)
    {
        if (strpos($name, '::') !== FALSE) {
            // back compatibility
            list(, $name) = explode('::', $name);
        }
        Nette\Utils\ObjectMixin::setExtensionMethod(__CLASS__, $name, $callback);
    }

 /**
  * Registers this control
  *
  * @return DateTimePicker
  */
 public static function register()
 {
     Container::extensionMethod('addDateTime', function ($container, $name, $label = NULL) {
         $picker = $container[$name] = new DateTimePicker($label);
         return $picker;
     });
 }