code: async def notifications(dev: Device, notification: str, listen_all: bool):
      
      notifications = await dev.get_notifications()
  
      async def handle_notification(x):
          click.echo("got notification: %s" % x)
  
      if listen_all:
          if notification is not None:
              await dev.services[notification].listen_all_notifications(
                  handle_notification
              )
          else:
              click.echo("Listening to all possible notifications")
              await dev.listen_notifications(fallback_callback=handle_notification)
  
      elif notification:
          click.echo("Subscribing to notification %s" % notification)
          for notif in notifications:
              if notif.name == notification:
                  await notif.activate(handle_notification)
  
          click.echo("Unable to find notification %s" % notification)
  
      else:
          click.echo(click.style("Available notifications", bold=True))
          for notification in notifications:
              click.echo("* %s" % notification)
docs: List available notifications and listen to them.
  
      Using --listen-all [notification] allows to listen to all notifications
       from the given subsystem.
      If the subsystem is omited, notifications from all subsystems are
      requested.