def test_minimum_delay(): assert letter_invader.delay(100, 10) == .1
def test_delay_second_state(): assert letter_invader.delay(23, 10) == .8
def test_delay_reduce_delay(): assert letter_invader.delay(10, 10) == .9
def test_delay_no_change(): assert letter_invader.delay(11, 10) == .9
def test_delay_first_state(): assert letter_invader.delay(2, 10) == 1