def METHOD_NAME(self):
    output = check_parse_tree(
        "foo | bar {test_special} | baz",
        Alternative([
            Literal(u"foo"),
            Literal(u"bar"),
            Literal(u"baz"),
        ]),
    )
    assert getattr(output.children[0], 'test_special', None) == None
    assert output.children[1].test_special == True
    assert getattr(output.children[2], 'test_special', None) == None