code: public function createResolver($apiName, array $config)
      {
          $factoryName = isset($config['resolver']) ? $config['resolver'] : ResolverFactory::class;
          $factory = $this->container->make($factoryName);
  
          if ($factory instanceof ResolverInterface) {
              return $factory;
          }
  
          if (!is_callable($factory)) {
              throw new RuntimeException("Factory {$factoryName} cannot be invoked.");
          }
  
          $resolver = $factory($apiName, $config);
  
          if (!$resolver instanceof ResolverInterface) {
              throw new RuntimeException("Factory {$factoryName} did not create a resolver instance.");
          }
  
          return $resolver;
      }
docs: Create a resolver.
  
  @param string $apiName
  @param array $config
  @return ResolverInterface