code: def receive_ping(self, ping: Ping):
          
  
          self.log_healthcheck.debug(
              'Ping received',
              message_id=ping.nonce,
              message=ping,
              sender=pex(ping.sender),
          )
  
          pong = Pong(nonce=ping.nonce)
          self.raiden.sign(pong)
  
          try:
              self.maybe_send(ping.sender, pong)
          except (InvalidAddress, UnknownAddress) as e:
              self.log.debug("Couldn't send the `Delivered` message", e=e)
docs: Handle a Ping message by answering with a Pong.