use Twig\Extension\AbstractExtension;
 use Twig\TwigFunction;

 final class TerminologyExtension extends AbstractExtension
 {
     public function getFunctions(): array
     {
         return [
-            new TwigFunction('resolve', [$this, 'resolve']);
+            new TwigFunction('resolve', $this->resolve(...)),
         ];
     }

     private function resolve($value)
     {
         return $value + 100;
     }
 }