def find_track(self, artist, title=None):
"""
Find tracks for a specific artist or filtering with a track title
- >>> player.find_track('The Beatles')
- >>> player.find_track('Nirvana', title='Smells Like Teen Spirit')
+ >>> player.find_track(Artist('The Beatles'))
+ >>> player.find_track(Artist('Nirvana'), title='Smells Like Teen Spirit')
Returns a list of Track objects
"""