code: protected function createSystemProperties(string $class, array $data): SystemPropertiesInterface
      {
          $sys = $data['sys'];
  
          if (isset($sys['space']) && !$sys['space'] instanceof ResourceInterface) {
              $sys['space'] = $this->client->getSpace();
          }
  
          if (isset($sys['environment']) && !$sys['environment'] instanceof ResourceInterface) {
              $sys['environment'] = $this->client->getEnvironment();
          }
  
          if (isset($sys['contentType']) && !$sys['contentType'] instanceof ResourceInterface) {
              $sys['contentType'] = $this->client->getContentType($sys['contentType']['sys']['id']);
          }
  
          return new $class($sys);
      }
docs: @param string $class
  @param array  $data
  
  @return SystemPropertiesInterface