When a track is skipped some services want to know about that (i.e. Grooveshark, rdio) to report the usage rate.

base.py

class TracklistProvider(object):
    def get_random(self):
        pass
    def set_random(self):
        pass
    def get_repeat(self):
        pass
    def get_consume(self):
        pass
    def set_consume(self):
        pass
    def next_track(self, current_track):
        pass
    def previous_track(self, current_track):
        pass
    def add(self, tracks=None, at_position=None, uri=None):
        pass
    def clear(self):
        pass
    def filter(self, criteria=None, **kwargs):
        pass
    def index(self, tl_track):
        pass
    def move(self, start, end, to_position):
        pass
    def remove(self, criteria=None, **kwargs):
        pass
    def shuffle(self, start=None, end=None):
        pass
    def slice(self, start, end):
        pass
    def track_change(self, reason, track):
        pass
    def get_tracklist(self):
        pass