NonNullElements j = new NonNullElements(KEY.PLAYERS, world);
NonNullElements j = new NonNullElements(KEY.PLAYERS, world, Player.AUTHORITATIVE);
    private void buildTrains() {	NonNullElements j = new NonNullElements(KEY.PLAYERS, world);	while (j.next()) {	    FreerailsPrincipal principal = ((Player)		    j.getElement()).getPrincipal();	    for (int i = 0; i < world.size(KEY.STATIONS, principal); i++) {		StationModel station = (StationModel)world.get(KEY.STATIONS, i,			principal);		if (null != station && null != station.getProduction()) {		    ProductionAtEngineShop production = station.getProduction();		    Point p = new Point(station.x, station.y);		    		    tb.buildTrain (production.getEngineType(),			 production.getWagonTypes(), p, principal);		    moveExecuter.processMove(new ChangeProductionAtEngineShopMove(				production, null, i, principal));		}	    }	}    }