code: protected function createServices(ContainerBuilder $container, $classes, $config, $tag, $method)
      {
          if (!is_array($tag)) {
              $tag = [$tag];
          }
  
          foreach ($classes as $class) {
              $methods = $this->getMethods($class);
              $definition = new Definition($class);
              $this->setProperties($definition, $config, $methods);
              $this->setTags($definition, $tag, $method);
              $container->setDefinition($this->getServiceName($tag[0]), $definition);
          }
      }
docs: Creates service definitions.
  
  @param ContainerBuilder $container
  @param string[]         $classes
  @param array            $config
  @param string|string[]  $tag
  @param string           $method