def test_example2(self):
self.assertEqual("31/9/73 is illegal", bestbefore.bestbefore("31/9/73"))
def test_invalidLeapYear(self):
self.assertEqual("02/29/2011 is illegal", bestbefore.bestbefore("02/29/2011"))
def test_example1(self):
self.assertEqual("2067-02-04", bestbefore.bestbefore("02/4/67"))
def test_validLeapYear(self):
self.assertEqual("2012-02-29", bestbefore.bestbefore("02/29/2012"))
