plcont: Use new ._cached() constructor
plcont: Use new ._cached() constructor

felix1m/pyspotify,jodal/pyspotify,kotamat/pyspotify,mopidy/pyspotify,felix1m/pyspotify,jodal/pyspotify,felix1m/pyspotify,mopidy/pyspotify,kotamat/pyspotify,jodal/pyspotify,kotamat/pyspotify