Sonata\PriceBundle\DependencyInjection\Configuration::addPriceSection PHP Method

    private function addPriceSection(ArrayNodeDefinition $node)
    {
        $node->children()->scalarNode('currency')->isRequired()->validate()->ifNotInArray(array_keys(Intl::getCurrencyBundle()->getCurrencyNames()))->thenInvalid("Invalid currency '%s'")->end()->end()->end();
    }