class UnprocessableHttpEntityException

class UnprocessableHttpEntityException extends HttpException {
  use DependencySerializationTrait;
  
  /**
   * The constraint violations associated with this exception.
   *
   * @var \Drupal\Core\Entity\EntityConstraintViolationListInterface
   */
  protected $violations;
  
  /**
   * UnprocessableHttpEntityException constructor.
   *
   * @param \Throwable|null $previous
   *   The pervious error, if any, associated with the request.
   * @param array $headers
   *   The headers associated with the request.
   * @param int $code
   *   The HTTP status code associated with the request. Defaults to zero.
   */
  public function __construct(?\Throwable $previous = NULL, array $headers = [], $code = 0) {
    parent::__construct(422, "Unprocessable Entity: validation failed.", $previous, $headers, $code);
  }
  
  /**
   * Gets the constraint violations associated with this exception.
   *
   * @return \Drupal\Core\Entity\EntityConstraintViolationListInterface
   *   The constraint violations.
   */
  public function getViolations() {
    return $this->violations;
  }
  
  /**
   * Sets the constraint violations associated with this exception.
   *
   * @param \Drupal\Core\Entity\EntityConstraintViolationListInterface $violations
   *   The constraint violations.
   */
  public function setViolations(EntityConstraintViolationListInterface $violations) {
    $this->violations = $violations;
  }

}