trait SessionTestTrait in Drupal 9

trait SessionTestTrait {

  /**
   * The name of the session cookie.
   *
   * @var string
   */
  protected $sessionName;

  /**
   * Generates a session cookie name.
   *
   * @param string $data
   *   The data to generate session name.
   */
  protected function generateSessionName($data) {
    $prefix = Request::createFromGlobals()
      ->isSecure() ? 'SSESS' : 'SESS';
    $this->sessionName = $prefix . substr(hash('sha256', $data), 0, 32);
  }

  /**
   * Returns the session name in use on the child site.
   *
   * @return string
   *   The name of the session cookie.
   */
  protected function getSessionName() {
    return $this->sessionName;
  }

}