/**
* {@inheritdoc}
*/
public function submitForm(array &$form, FormStateInterface $form_state)
{
$sitemap = new Simplesitemap();
$settings = $sitemap->get_settings();
$settings['max_links'] = $form_state->getValue('max_links');
$sitemap->save_settings($settings);
parent::submitForm($form, $form_state);
}
