code: def vrrp_config(app, interface, config):
      
      config_request = vrrp_event.EventVRRPConfigRequest(interface, config)
      config_request.sync = True
      return app.send_request(config_request)
docs: create an instance.
      returns EventVRRPConfigReply(instance.name, interface, config)
      on success.
      returns EventVRRPConfigReply(None, interface, config)
      on failure.