public static function fromJson($json)
 {
     if (is_object($json)) {
         $policy = new QuotaPolicy();
         if (isset($json->quotas)) {
             $policy->setQuotas($json->quotas);
         }
         return $policy;
     }
     return NULL;
 }
 public function getBucketQuota($bucket_name)
 {
     $uri = $this->formatUri($this->fds_config->getBaseUri(), $bucket_name, SubResource::QUOTA);
     $headers = $this->prepareRequestHeader($uri, Http::GET, Mime::JSON);
     $response = $this->invoke(Action::GetBucketQuota, $uri, $headers, Http::GET, Mime::JSON, null);
     if ($response->code == self::HTTP_OK) {
         $policy = QuotaPolicy::fromJson($response->body);
         return $policy;
     } else {
         $message = "Get bucket quota failed, status=" . $response->code . ", bucket_name=" . $bucket_name . ", reason=" . $response->raw_body;
         $this->printResponse($response);
         throw new GalaxyFDSClientException($message);
     }
 }