old_contents: import logging
  import multiprocessing
  
  from spotify import Link
  
  from mopidy.backends.base import BaseLibraryController
  from mopidy.backends.libspotify import ENCODING
  from mopidy.backends.libspotify.translator import LibspotifyTranslator
  
  logger = logging.getLogger('mopidy.backends.libspotify.library')
  
  class LibspotifyLibraryController(BaseLibraryController):
      def find_exact(self, **query):
          return self.search(**query)
  
      def lookup(self, uri):
          spotify_track = Link.from_string(uri).as_track()
          # TODO Block until metadata_updated callback is called. Before that the
          # track will be unloaded, unless it's already in the stored playlists.
          return LibspotifyTranslator.to_mopidy_track(spotify_track)
  
      def refresh(self, uri=None):
          pass # TODO
  
      def search(self, **query):
          spotify_query = []
          for (field, values) in query.iteritems():
              if not hasattr(values, '__iter__'):
                  values = [values]
              for value in values:
                  if field == u'track':
                      field = u'title'
                  if field == u'any':
                      spotify_query.append(value)
                  else:
                      spotify_query.append(u'%s:"%s"' % (field, value))
          spotify_query = u' '.join(spotify_query)
          logger.debug(u'Spotify search query: %s' % spotify_query)
          my_end, other_end = multiprocessing.Pipe()
          self.backend.spotify.search(spotify_query.encode(ENCODING), other_end)
          my_end.poll(None)
          playlist = my_end.recv()
          return playlist
  
new_contents: import logging
  import multiprocessing
  
  from spotify import Link
  
  from mopidy.backends.base import BaseLibraryController
  from mopidy.backends.libspotify import ENCODING
  from mopidy.backends.libspotify.translator import LibspotifyTranslator
  from mopidy.models import Playlist
  
  logger = logging.getLogger('mopidy.backends.libspotify.library')
  
  class LibspotifyLibraryController(BaseLibraryController):
      def find_exact(self, **query):
          return self.search(**query)
  
      def lookup(self, uri):
          spotify_track = Link.from_string(uri).as_track()
          # TODO Block until metadata_updated callback is called. Before that the
          # track will be unloaded, unless it's already in the stored playlists.
          return LibspotifyTranslator.to_mopidy_track(spotify_track)
  
      def refresh(self, uri=None):
          pass # TODO
  
      def search(self, **query):
          if not query:
              # Since we can't search for the entire Spotify library, we return
              # all tracks in the stored playlists when the query is empty.
              tracks = []
              for playlist in self.backend.stored_playlists.playlists:
                  tracks += playlist.tracks
              return Playlist(tracks=tracks)
          spotify_query = []
          for (field, values) in query.iteritems():
              if not hasattr(values, '__iter__'):
                  values = [values]
              for value in values:
                  if field == u'track':
                      field = u'title'
                  if field == u'any':
                      spotify_query.append(value)
                  else:
                      spotify_query.append(u'%s:"%s"' % (field, value))
          spotify_query = u' '.join(spotify_query)
          logger.debug(u'Spotify search query: %s' % spotify_query)
          my_end, other_end = multiprocessing.Pipe()
          self.backend.spotify.search(spotify_query.encode(ENCODING), other_end)
          my_end.poll(None)
          playlist = my_end.recv()
          return playlist
  
subject: Return all tracks in stored playlists upon empty search query