public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(['data_class' => null])->setDefined('fields')->setAllowedTypes('fields', 'array')->setDefined('type')->setAllowedValues('type', [StringFilter::TYPE_CONTAINS, StringFilter::TYPE_NOT_CONTAINS, StringFilter::TYPE_EQUAL, StringFilter::TYPE_EMPTY, StringFilter::TYPE_NOT_EMPTY, StringFilter::TYPE_STARTS_WITH, StringFilter::TYPE_ENDS_WITH, StringFilter::TYPE_IN, StringFilter::TYPE_NOT_IN]);
}