def test_is_valid_rnd(self):
invalids = (random.randint(0, 999999999), random.randint(10000000000, 999999999999),
random.randint(10000000000000, 9999999999999999))
for x in invalids:
self.assertFalse(is_valid(x), x)
def test_is_valid(self):
self.assertTrue(is_valid(1234567891))
self.assertTrue(is_valid(1000000000))
self.assertFalse(is_valid(999999999))
self.assertFalse(is_valid(0))
self.assertFalse(is_valid(1.0000000000))