code: private function registerFactories(ContainerBuilder $container)
      {
          $defaultConfig = [];
  
          $builder = $container->getDefinition('payum.builder');
  
          $builder->addMethodCall('addGatewayFactoryConfig', [
              Offline\Constants::FACTORY_NAME,
              $defaultConfig,
          ]);
          $builder->addMethodCall('addGatewayFactory', [
              Offline\Constants::FACTORY_NAME,
              [Offline\OfflineGatewayFactory::class, 'build'],
          ]);
  
          $builder->addMethodCall('addGatewayFactoryConfig', [
              Outstanding\Constants::FACTORY_NAME,
              $defaultConfig,
          ]);
          $builder->addMethodCall('addGatewayFactory', [
              Outstanding\Constants::FACTORY_NAME,
              [Outstanding\OutstandingGatewayFactory::class, 'build'],
          ]);
  
          $builder->addMethodCall('addGatewayFactoryConfig', [
              Credit\Constants::FACTORY_NAME,
              $defaultConfig,
          ]);
          $builder->addMethodCall('addGatewayFactory', [
              Credit\Constants::FACTORY_NAME,
              [Credit\CreditGatewayFactory::class, 'build'],
          ]);
      }
docs: Registers the required factories.
  
  @param ContainerBuilder $container