def test_list_songs_with_songs_works(self):
ml = MediaLibrary()
s1 = song()
s2 = song()
s3 = song()
ml.add_song(s1)
ml.add_song(s2)
ml.add_song(s3)
self.assertListEqual(ml.list_songs(), [s1, s2, s3])
def test_list_songs_without_songs_works(self):
ml = MediaLibrary()
self.assertListEqual(ml.list_songs(), [])