public function add($alert, $class = 'danger', $dismissible = true)
    {
        $alertDefault = array(
            'alert' => '',
            'class' => $class,
            'dismissible' => $dismissible,
        );
        if (!\is_array($alert)) {
            $alert = array(
                'alert' => $alert,
            );
        } else {
            foreach (array('alert','class','dismissible') as $i => $key) {
                if (isset($alert[$i])) {
                    $alert[$key] = $alert[$i];
                    unset($alert[$i]);
                }
            }
        }
        $alert = \array_merge($alertDefault, $alert);
        if (\strlen($alert['alert'])) {
            // $this->debug->warn('adding alert', $alert);
            $this->alerts[] = $alert;
        }
    }