code: def service_provider(*services):
      
  
      def real_decorator(clazz):
          instance = clazz()
          for service in services:
              global_lookup.add(service, instance)
          return clazz
  
      return real_decorator
docs: This is a class decorator that declares a class to provide a set of services.
      It is expected that the class has a no-arg constructor and will be instantiated
      as a singleton.