protected function renderButtons()
    {
        // Box tools
        if ($this->buttonsTemplate !== null && !empty($this->boxTools)) {
            // Begin box tools
            echo Html::beginTag('div', ['class' => 'box-tools pull-right']);
            echo preg_replace_callback('/\\{([\w\-\/]+)\\}/', function ($matches) {
                $name = $matches[1];
                if (isset($this->boxTools[$name])) {
                    $label = isset($this->boxTools[$name]['label']) ? $this->boxTools[$name]['label'] : '';

                    $icon = isset($this->boxTools[$name]['icon']) ? Html::tag('i', '', ['class' => 'fa ' . $this->boxTools[$name]['icon']]) : '';
                    $label = $icon . ' ' . $label;
                    $this->boxTools[$name]['options']['class'] = isset($this->boxTools[$name]['options']['class']) ? 'btn btn-sm ' . $this->boxTools[$name]['options']['class'] : 'btn btn-sm';

                    return Html::button($label, $this->boxTools[$name]['options']);
                } else {
                    return '';
                }
            }, $this->buttonsTemplate);
            // End box tools
            echo Html::endTag('div');
        }
    }