/**
  * Adds an error to this document
  * @param JsonApiError $error Error to add
  * @return null
  */
 public function addError(JsonApiError $error)
 {
     $this->errors[] = $error;
     if (!$this->statusCode && $error->getStatusCode()) {
         $this->statusCode = $error->getStatusCode();
     }
 }