/**
  * {@inheritdoc}
  */
 public function setDefaultOptions(OptionsResolverInterface $resolver)
 {
     parent::setDefaultOptions($resolver);
     $resolver->setDefaults(['empty_value' => false, 'choices' => function (Options $options) {
         return $this->getChoices($options['association_class']);
     }, 'multiple' => true, 'expanded' => true]);
 }
 /**
  * {@inheritdoc}
  */
 public function setDefaultOptions(OptionsResolverInterface $resolver)
 {
     parent::setDefaultOptions($resolver);
     $resolver->setDefaults(['empty_value' => false, 'choices' => ['No', 'Yes']]);
 }