code: func (n *networkNamespace) programRoute(path string, dest *net.IPNet, nh net.IP) error {
  	gwRoutes, err := n.nlHandle.RouteGet(nh)
  	if err != nil {
  		return fmt.Errorf("route for the next hop %s could not be found: %v", nh, err)
  	}
  
  	return n.nlHandle.RouteAdd(&netlink.Route{
  		Scope:     netlink.SCOPE_UNIVERSE,
  		LinkIndex: gwRoutes[0].LinkIndex,
  		Gw:        nh,
  		Dst:       dest,
  	})
  }
docs: // Program a route in to the namespace routing table.