human
Solve the following python programming problem given the following code:
def _make_class_unpicklable(cls) : 
    'Make the given class un-picklable.' 
    def _break_on_call_reduce(self, protocol = None) : 
        raise TypeError (('%r cannot be pickled' % self)) 
cls.__reduce_ex__ = <MASK> 
    cls.__module__ = '<unknown>' 
    
    Given the code above, what is a proper replacement for <MASK>? Choose among: cls
assistant
#Here is a proper replacement for <MASK>.
def _break_on_call_reduce(