def test_star(a):
    starA = a.star()
    assert starA.accepts('')
    assert starA.accepts('a')
    assert (not starA.accepts('b'))
    assert starA.accepts('aaaaaaaaa')
def test_star(a):
    starA = a.star()
    assert starA.accepts()
    assert starA.accepts('a')
    assert (not starA.accepts('b'))
    assert starA.accepts('aaaaaaaaa')