def test_update_artists(self):
artist = Artist('my_artist_name')
artist.add_track('my_track_name', '10/01/01')
artist.add_track('my_second_track_name', '10/01/01')
artist2 = Artist('my_artist_name')
artist2.add_track('my_track_name', '11/01/01')
artist2.add_track('my_second_track_name', '11/01/01')
#This one will not be added because it is the same date
artist2.add_track('my_track_name', '11/01/01')
artist.update(artist2)
self.assertEqual(len(artist), 4)
artist3 = Artist('my_other_artist_name')
artist3.add_track('my_track_name', '11/01/01')
self.assertRaises(AttributeError, artist.update, artist3)
self.assertEqual(len(artist), 4)
