/**
  * {@inheritdoc}
  */
 public function buildConfigurationForm(array $form, FormStateInterface $form_state)
 {
     $form = parent::buildConfigurationForm($form, $form_state);
     // Remove to_sid. User can't set it, since we want a dynamic 'next' state.
     unset($form['to_sid']);
     return $form;
 }
 /**
  * {@inheritdoc}
  */
 public function buildConfigurationForm(array $form, FormStateInterface $form_state)
 {
     $form = parent::buildConfigurationForm($form, $form_state);
     return $form;
 }