human
Solve the following python programming problem given the following code:
@ classmethod 
def _with_register_classes(cls, fn) : 
    'Run a setup method, framing the operation with a Base class
        that will catch new subclasses to be established within
        the "classes" registry.

        ' 
    cls_registry = fn.classes 
    class FindFixture (type) : 
        def __init__(cls, classname, bases, dict_) : 
            cls_registry [classname] = cls 
            return type.__init__ (cls, classname, bases, dict_) 
class _Base (util.with_metaclass (FindFixture, object)) : 
        pass 
class Basic (BasicEntity, _Base) : 
        pass 
class Comparable (ComparableEntity, _Base) : 
        pass 
cls.Basic = Basic 
    cls.Comparable = Comparable 
    fn () 

    
    

    Fix the buggy line: cls_registry = fn.classes
assistant
#Here is Python program to fix the buggy line: cls_registry = fn.

cls_registry = cls.classes