public function addButton(string $title = null, array $options = []): string
    {
        if (!$title) {
            $title = __d('ck_tools', 'add');
        }
        $options = Hash::merge([
            'url' => null,
            'icon' => 'fa fa-plus',
            'class' => 'btn btn-default btn-xs btn-add',
        ], $options);
        $url = $options['url'];
        if (!$url) {
            $url = ['action' => 'add'];
            $url = $this->augmentUrlByBackParam($url);
        }
        $icon = $options['icon'];
        unset($options['url'], $options['icon']);
        if ($icon) {
            $title = '<i class="' . $icon . '"></i> ' . '<span class="button-text">' . $title . '</span>';
            $options['escape'] = false;
        }

        return $this->Html->link($title, $url, $options);
    }