code: public <Source extends RouteSource, Destination extends RouteDestination> RoutingBuilder add(Route<Source, Destination> route) {
          routes.add(route);
          return this;
      }
docs: Adds a {@link Route} to the {@link RoutingTable}.
  
  @param route         {@link Route} to be added.
  @param <Source>      {@link RouteSource} type.
  @param <Destination> {@link RouteDestination} type.
  @return This builder.