protected function configureAdditionalImage(OptionsResolver $resolver)
    {
        $resolver
            ->setRequired(['prefix', 'width', 'height'])
            ->setOptional(['mode'])
            ->setDefaults(['mode' => 'fit'])
            ->addAllowedTypes(
                [
                    'prefix' => 'string',
                    'mode' => 'string',
                    'width' => 'integer',
                    'height' => 'integer',
                ]
            )
            ->addAllowedValues(['mode' => ['crop', 'resize', 'fit']]);

        return $this;
    }