src/Ease/TWB/ButtonGroup.php
public function addButton($content, $type = 'default', $properties = [])
    {
        if (isset($properties['class'])) {
            $properties['class'] = 'btn btn-'.$type.' '.$properties['class'];
        } else {
            $properties['class'] = 'btn btn-'.$type;
        }
        $button = new \Ease\Html\ButtonTag($content, $properties);
        return $this->addItem($button);
    }
public function addButton($content, $type = 'default', $properties = [])
    {
        if (isset($properties['class'])) {
            $properties['class'] = 'btn btn-'.$type.' '.$properties['class'];
        } else {
            $properties['class'] = 'btn btn-'.$type;
        }
        $button = new \Ease\Html\ButtonTag($content, $properties);
        return $this->addItem($button);
    }
Add new button into Group

@param mixed  $content    Button content
@param string $type       default|info|success|warning|danger
@param array  $properties adittional properties
@return \Ease\Html\ButtonTag Button inserted