protected function setMixins(Metadata\Interfaces\MixinInterface $metadata, array $mixins)
    {
        foreach ($mixins as $mixinName) {
            $mixinMeta = $this->loadMetadataForMixin($mixinName);
            if (null === $mixinMeta) {
                continue;
            }
            $metadata->addMixin($mixinMeta);
        }
        return $metadata;
    }