private function getOrmTargetEntityResolverNode()
    {
        $treeBuilder = new TreeBuilder('resolve_target_entities');

        if (method_exists($treeBuilder, 'getRootNode')) {
            $node = $treeBuilder->getRootNode();
        } else {
            // BC layer for symfony/config 4.1 and older
            $node = $treeBuilder->root('resolve_target_entities');
        }

        $node
            ->useAttributeAsKey('interface')
            ->prototype('scalar')
                ->cannotBeEmpty()
            ->end();

        return $node;
    }