public function buttonGroup($buttons, array $options = [])
{
$options += ['vertical' => false];
$vertical = $options['vertical'];
unset($options['vertical']);
$options = $this->addClass($options, 'btn-group');
if ($vertical) {
$options = $this->addClass($options, 'btn-group-vertical');
}
return $this->Html->tag('div', implode('', $buttons), $options);
}