code: def reactToAMQPMessage(message, send_back):
      
      if _instanceof(message, structures.ScanFile):
          result = antivirus.save_and_scan(
              message.filename,
              message.b64_data
          )
          return structures.ScanResult(message.filename, result)
  
      elif _instanceof(message, structures.UpdateDatabase):
          return structures.DatabaseUpdated(
              antivirus.update_database()
          )
  
      raise ValueError(
          "Unknown type of request: '" + str(type(message)) + "'!"
      )
docs: React to given (AMQP) message. `message` is expected to be
      :py:func:`collections.namedtuple` structure from :mod:`.structures` filled
      with all necessary data.
  
      Args:
          message (object): One of the request objects defined in
                            :mod:`.structures`.
          send_back (fn reference): Reference to function for responding. This is
                    useful for progress monitoring for example. Function takes
                    one parameter, which may be response structure/namedtuple, or
                    string or whatever would be normally returned.
  
      Returns:
          object: Response class from :mod:`structures`.
  
      Raises:
          ValueError: if bad type of `message` structure is given.