public function buttonGroup($buttons, array $options = []) {
        $options += [
            'vertical' => false,
            'templateVars' => []
        ];
        if ($options['vertical']) {
            $options = $this->addClass($options, 'btn-group-vertical');
        }
        return $this->formatTemplate('buttonGroup', [
            'content' => implode('', $buttons),
            'attrs' => $this->templater()->formatAttributes($options, ['vertical']),
            'templateVars' => $options['templateVars']
        ]);
    }