ThemeNegotiator example

/** * Creates a new theme negotiator instance. * * @param array $negotiators * An array of negotiator IDs. * * @return \Drupal\Core\Theme\ThemeNegotiator */
  protected function createThemeNegotiator(array $negotiators) {
    $resolver = new ClassResolver();
    $resolver->setContainer($this->container);
    $theme_negotiator = new ThemeNegotiator($this->themeAccessCheck, $resolver, $negotiators);
    return $theme_negotiator;
  }

}