def test_get_keywords_exists(self):
cmd = Command()
cmd.append('command_1', ['keyword_1', 'keyword_2'])
cmd.append('command_2', ['keyword_3', 'keyword_4'])
self.assertEqual('command_1', cmd.get('keyword_1'))
self.assertEqual('command_1', cmd.get('keyword_2'))
self.assertEqual('command_2', cmd.get('keyword_3'))
self.assertEqual('command_2', cmd.get('keyword_4'))
def test_get_keywords_do_not_exist(self):
cmd = Command()
self.assertIsNone(cmd.get('keyword_1'))
self.assertIsNone(cmd.get('keyword_2'))
