Plugin Question

[Steve <steve thatbytes co uk>]

I have wrote the plugin below:

from __future__ import absolute_import

__kupfer_name__ = _("Spotify")
__kupfer_sources__ = ("SpotifySource", )
__description__ = _("Control spofity media player.")
__version__ = "0.1"
__author__ = "Stephen Johnson <steve thatbytes co uk>"

import dbus

from kupfer.objects import RunnableLeaf, Source
from kupfer.obj.apps import AppLeafContentMixin
from kupfer import utils, icons, pretty

import pynotify

class PlayPause (RunnableLeaf):
	def run(self):
		RunnableLeaf.__init__(self, name=_("Play/Pause"))
		session = dbus.SessionBus.get_session()
    		self.spotify =
session.get_object("org.mpris.MediaPlayer2.spotify","/org/mpris/MediaPlayer2")
		self.spotify.PlayPause()	
	def get_description(self):
		return _("Resume/Pause playback in Spotify")
	def get_icon_name(self):
		return "media-playback-start"
class Next (RunnableLeaf):
	def __init__(self):
   		session = dbus.SessionBus.get_session()
	        self.spotify =
session.get_object("org.mpris.MediaPlayer2.spotify","/org/mpris/MediaPlayer2")
		RunnableLeaf.__init__(self, name=_("Next"))
	def run(self):
		self.spotify.Next()
	def get_description(self):
		return _("Jump to next track in Spotify")
	def get_icon_name(self):
		return "media-skip-forward"

class Previous (RunnableLeaf):
	def __init__(self):
		RunnableLeaf.__init__(self, name=_("Previous"))
	def run(self):
		session = dbus.SessionBus.get_session()
                self.spotify =
session.get_object("org.mpris.MediaPlayer2.spotify","/org/mpris/MediaPlayer2")
		self.spotify.Previous()
	def get_description(self):
		return _("Jump to previous track in Previos")
	def get_icon_name(self):
		return "media-skip-backward"
class SpotifySource (AppLeafContentMixin, Source):
	appleaf_content_id = 'spotify'
	def __init__(self):
		Source.__init__(self, _("Spotify"))
	def get_items(self):
		yield PlayPause()
		yield Next()
		yield Previous()
	def provides(self):
		yield RunnableLeaf
	def get_description(self):
		return __description__
	def get_icon_name(self):
		return "spotify"



Im just wondering how i can change its behaviour so that so its spotify
-> Next. Please forgive my ignorance but im finding the documentation
hard to get through.