protected function renderToggleButton()
    {
        if (!isset($this->toggleButtonOptions['options']['data-target'])) {
            $this->toggleButtonOptions['options']['data-target'] = $this->options['id'];
        }
        Html::addCssClass($this->toggleButtonOptions['options'], ['toggle-button' => 'dropdown-trigger']);

        return Button::widget($this->toggleButtonOptions);
    }