def test_empty(self): self.assertIs(validate(''), False)
def test_zero(self): self.assertIs(validate('0'), True)
def test_not_valid(self): self.assertIs(validate('4123412341234123'), False)
def test_amex(self): self.assertIs(validate('343539069275686'), True)
def test_mastercard(self): self.assertIs(validate('5490745468338088'), True)
def test_visa_no_nines(self): self.assertIs(validate('4743803307345687'), True)
def test_visa(self): self.assertIs(validate('4743903107345687'), True)