PhpBrew\VariantBuilder::getVariantNames PHP Method

    public function getVariantNames()
    {
        return array_keys($this->variants);
    }

 public function arguments($args)
 {
     $args->add('version')->suggestions(array('5.3', '5.4', '5.5'));
     $args->add('variants')->multiple()->suggestions(function () {
         $variants = new VariantBuilder();
         $list = $variants->getVariantNames();
         sort($list);
         return array_map(function ($n) {
             return '+' . $n;
         }, $list);
     });
 }