question: public static EnergyNetwork initNetwork ( ) { Random random = new Random ( System . currentTimeMillis ( ) ) ; int id = random . nextInt ( ) ; while ( usedIds . contains ( id ) ) { id = random . nextInt ( ) ; } ; EnergyNetwork net = new EnergyNetwork ( ) ; usedIds . add ( id ) ; net . networkID = id ; return net ; }
target:  Create a new network and get an ID