def METHOD_NAME(each_version):
    """
    Jedi splits parameters into params, this is not what the grammar does,
    but Jedi does this to simplify argument parsing.
    """
    def check(src, result):
        m = parse(src, version=each_version)
        assert not list(m.iter_funcdefs())
    check('def x(a, (b, c)):\n pass', ['a'])
    check('def x((b, c)):\n pass', [])