def test_equals_2(self):
     self.assertEqual(get_issuer(4111111111111), 'VISA')
 def test_equals_8(self):
     self.assertEqual(get_issuer(9111111111111111), 'Unknown')
 def test_equals_7(self):
     self.assertEqual(get_issuer(5105105105105106), 'Mastercard')
 def test_equals_5(self):
     self.assertEqual(get_issuer(6011111111111117), 'Discover')
 def test_equals_4(self):
     self.assertEqual(get_issuer(378282246310005), 'AMEX')
 def test_equals_3(self):
     self.assertEqual(get_issuer(4012888888881881), 'VISA')