async def artwork(self):
        """Return an image file (png) for what is currently playing.

        None is returned if no artwork is available. Must be logged in.
        """
        art = await self.daap.get(_ARTWORK_CMD, daap_data=False)
        return art if art != b'' else None
Return an image file (png) for what is currently playing.

        None is returned if no artwork is available. Must be logged in.