code: def add_traffic_handler(self, netlink, netlink_gw=None, network=None):
          
          routing_node_gateway = RoutingNodeGateway(netlink,
              destinations=[] if not netlink_gw else netlink_gw)
          return self._add_gateway_node('netlink', routing_node_gateway, network)
docs: Add a traffic handler to a routing node. A traffic handler can be
          either a static netlink or a multilink traffic handler. If ``network``
          is not specified and the interface has multiple IP addresses, the 
          traffic handler will be added to all ipv4 addresses.
          
          Add a pre-defined netlink to the route table of interface 0::
          
              engine = Engine('vm')
              rnode = engine.routing.get(0)
              rnode.add_traffic_handler(StaticNetlink('mynetlink'))
          
          Add a pre-defined netlink only to a specific network on an interface
          with multiple addresses. Specify a netlink_gw for the netlink::
          
              rnode = engine.routing.get(0)
              rnode.add_traffic_handler(
                  StaticNetlink('mynetlink'),
                  netlink_gw=[Router('myrtr'), Host('myhost')],
                  network='172.18.1.0/24')
              
          :param StaticNetlink,Multilink netlink: netlink element
          :param list(Element) netlink_gw: list of elements that should be destinations
              for this netlink. Typically these may be of type host, router, group, server,
              network or engine. 
          :param str network: if network specified, only add OSPF to this network on interface
          :raises UpdateElementFailed: failure updating routing
          :raises ModificationAborted: Change must be made at the interface level
          :raises ElementNotFound: ospf area not found
          :return: Status of whether the route table was updated
          :rtype: bool