def METHOD_NAME(self, prepend, append, func_name, additions):
    func = getattr(self, func_name)
    expected = "\n".join(
        additions[0] + inspect.cleandoc(func.__doc__).splitlines() + additions[1]
    )
    wfunc = modify_docstring(prepend=prepend, append=append)(func)
    assert wfunc.__doc__ == expected