old_contents: class SingleTon(object):
      objs  = {}
      def __new__(cls, *args, **kv):
          if cls not in cls.objs:
              cls.objs[cls] = object.__new__(cls)
          return cls.objs[cls]
  
  
new_contents: 
  def get_instance(cls, *args, **kv):
      if cls in cls.objs:
          return cls.objs[cls]
      else:
          return cls(*args, **kv)
  
  class SingleTon(object):
      objs  = {}
      def __new__(cls, *args, **kv):
          if cls not in cls.objs:
              cls.objs[cls] = object.__new__(cls)
          return cls.objs[cls]
  
  
subject: add get_instance