human
Here's a good function header given the following:
I wrote the below code

    def decorator(func):
        fname = func.__name__
        old_func = getattr(cls, fname, None)
        if (old_func is not None):
            old_ref = ('_old_%s_%s' % (patch_name, fname))
            old_attr = getattr(cls, old_ref, None)
            if (old_attr is None):
                setattr(cls, old_ref, old_func)
            else:
                raise KeyError(('%s.%s    already    exists.' % (cls.__name__, old_ref)))
        setattr(cls, fname, func)
        return func
    return decorator

What's a good function header?
assistant
#Here's a good function header.

def monkeypatch_method(cls, patch_name):