public void updateJunction(Venue v, Tile t, boolean isMember) {
    if (t == null) {
      return ;
      //I.complain("CANNOT SUPPLY NULL TILE AS JUNCTION") ;
    }
    junctions.toggleMember(t, t, isMember) ;
    if (isMember) {
      ///I.say("Updating road junction "+t) ;
      for (Target o : junctions.visitNear(t, PATH_RANGE + 1, null)) {
        final Tile jT = (Tile) o ;
        routeBetween(t, jT) ;
      }
    }
    else {
      ///I.say("Discarding junctions for "+v) ;
      final List <Route> routes = tileRoutes.get(t) ;
      if (routes != null) {
        for (Route r : routes) {
          if (r.cost < 0) continue ;
          deleteRoute(r) ;
          r.cost = -1 ;
        }
      }
    }
  }