* @return An <code>Element</code> encapsulating this action.
     */
    public Element getNewTradeRoute(ServerPlayer serverPlayer) {
        List<TradeRoute> routes
            = new ArrayList<TradeRoute>(serverPlayer.getTradeRoutes());
        TradeRoute route = new TradeRoute(getGame(), "", serverPlayer);
        routes.add(route);
        serverPlayer.setTradeRoutes(routes);
        return new ChangeSet().addTradeRoute(serverPlayer, route)
            .build(serverPlayer);
    }