trait CacheableResponseTrait

trait CacheableResponseTrait {
    
    /**
     * The cacheability metadata.
     *
     * @var \Drupal\Core\Cache\CacheableMetadata
     */
    protected $cacheabilityMetadata;
    
    /**
     * {@inheritdoc}
     */
    public function addCacheableDependency($dependency) {
        // A trait doesn't have a constructor, so initialize the cacheability
        // metadata if that hasn't happened yet.
        if (!isset($this->cacheabilityMetadata)) {
            $this->cacheabilityMetadata = new CacheableMetadata();
        }
        $this->cacheabilityMetadata = $this->cacheabilityMetadata
            ->merge(CacheableMetadata::createFromObject($dependency));
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheableMetadata() {
        // A trait doesn't have a constructor, so initialize the cacheability
        // metadata if that hasn't happened yet.
        if (!isset($this->cacheabilityMetadata)) {
            $this->cacheabilityMetadata = new CacheableMetadata();
        }
        return $this->cacheabilityMetadata;
    }

}