code: public function createService($namespace, array $config = [])
      {
          $configuration = $this->config;
  
          if (isset($this->config[$namespace])) {
              $configuration = arrayMergeDeep($configuration, $this->config[$namespace]);
          }
  
          $configuration = arrayMergeDeep($configuration, $config);
  
          $service = "DTS\\eBaySDK\\{$namespace}\\Services\\{$namespace}Service";
  
          return new $service($configuration);
      }
docs: Create a service object by namespace. Service is configured using array of options.
  
  @param string $namespace Service namespace (e.g. Finding, Trading).
  @param array  $config Configuration options for the service.
  
  @return \DTS\eBaySDK\Services\BaseService