human
Solve the following python programming problem given the following code:
def __init__(cls, * args) : 
    cls._singleton_instance = None 
    old_cls_init = cls.__init__ 
    def __init_trap__(self, * args, **kwargs) : 
        if cls._singleton_instance : 
            raise RuntimeError ((('instance of ' + cls.__name__) + ' has already been created')) 
old_cls_init (self, * args, ** kwargs) 
        cls._singleton_instance = self 
cls.__init__ = old_cls_init 
    super (_SingletonMetaclass, cls).__init__ (* args) 

    
    

    Fix the buggy line: cls.__init__ = old_cls_init
assistant
#Here is Python program to fix the buggy line: cls.

cls.__init__ = def __init_trap__(