/**
  * {@inheritdoc}
  */
 public function buildForm(array $form, FormStateInterface $form_state, $method = NULL)
 {
     $definition = \Drupal::service('plugin.manager.uc_payment.method')->getDefinition($method);
     $form['#title'] = $this->t('@method settings', ['@method' => $definition['name']]);
     $this->instance = \Drupal::service('plugin.manager.uc_payment.method')->createInstance($method);
     $this->settings = $this->instance->getSettingsForm();
     $form = $this->settings->buildForm($form, $form_state);
     return parent::buildForm($form, $form_state);
 }
 /**
  * {@inheritdoc}
  */
 public function submitForm(array &$form, FormStateInterface $form_state)
 {
     parent::submitForm($form, $form_state);
     $this->plugin->submitConfigurationForm($form['settings'], $form_state);
 }