human
Solve the following python programming problem given the following code:
def copy_class(source) : 
    def decorator(cls) : 
        f = (lambda k : ((k not in cls.__dict__) and (not k.startswith ('__')))) 
        for k in filter (f, source.__dict__.keys ()) : 
            setattr (cls, k, source.__dict__ [k]) 
return cls 
return source 

    
    

    Fix the buggy line: return source
assistant
#Here is Python program to fix the buggy line: return source
.

return def decorator(