docs: def available_players():
      """Searchs and returns set of unique names of objects
      which implements MPRIS2 interfaces.
  
      :returns: set of unique names.
      :type: set
      """
      bus = dbus.SessionBus()
      players = set()
      for name in filter(lambda item: item.startswith(MPRIS_NAME_PREFIX),
                         bus.list_names()):
          owner_name = bus.get_name_owner(name)
          players.add(convert(owner_name))
      return players