class Singleton(object):

    def __new__(cls):

        if not hasattr(cls, 'instance'):

            cls.instance = super(Singleton, cls).__new__(cls)

        return cls.instance

s1 = Singelton()

s2 = Singleton()

class HealthCheck:

    _instance = None

    def __new__(cls, *args, **kwargs):

        if not HealthCheck._instance:

            HealthCheck._instance = super(HealthCheck, cls).__new__(cls, *args, **kwargs)

        return HealthCheck._instance

    def __init__(self):

        self.servers = []

    def do1(self):

       pass

    def do2(self):

        pass

 class MetaSingleton(type):

     _instance = {}

     def __call__(cls, *args, **kwargs):

         if cls not in cls._instance:

             cls._instance[cls] = super(MetaSingleton, cls).__call__(*args, **kwargs)

         return cls._instance

 class Logger(metaclass = MetaSingleton):

     pass

 logger1 = Logger()

 logger2 = Logger()

 class Actor(object):

     def __init__(self):

         self.isBusy = False

     def occupied(self):

         self.isBusy = True

         print(type(self).__name__, "is occupied with current movie")

     def available(self):

         self.isBusy = False

         print(type(self).__name__, "is free for the movie")

     def getStatus(self):

     return self.isBusy

 class Agent(object):

     def __init__(self):

         self.principal = None

     def __work(self):

         self.actor = Actor()

         if self.actor.getStatus():

             self.actor.occupied()

         else:

             self.available()

 if __name__ == '__main__':

     r = Agent()

     r.work()