def test_get_words_incorrect_username(self):
self.assertEqual(get_words("@user I'm a message", 'username'), [])
def test_get_words_correct_username(self):
self.assertEqual(get_words("@user I'm a message", 'user'),
['@user', "I'm", 'a', 'message'])
def test_get_words_no_username(self):
self.assertEqual(get_words("Hi, I'm a test message.", ''), [])