private static void printNuNetDescription(List<String> command) {
   String varname = "default";
   if (command.size() > 1) varname = command.get(1);
   NuNet net = nunets.get(varname);
   if (net == null) {
     System.out.println("No nu*-net loaded under name '" + varname + "'");
     return;
   }
   //		System.out.println("Nu*-net '"+varname+"':");
   System.out.println(net.getPlaces().size() + " places: " + net.getPlaces());
   System.out.println(net.getTransitions().size() + " transitions: " + net.getTransitions());
   System.out.println(net.getFlowRelationships().size() + " arcs: " + net.getFlowRelationships());
   System.out.print(net.getInitialMarking().getNumTokens() + " tokens and ");
   System.out.println(
       net.getInitialMarking().getNames().size()
           + " names in the initial marking: "
           + net.getInitialMarking().getNames());
   System.out.println("Initial marking: " + net.getInitialMarking().toString());
 }
  private static void doSimulate(NuNet net) {
    Interpreter interpreter = new Interpreter();
    Marking marking = net.getInitialMarking();
    while (true) {
      List<EnabledTransition> modes = interpreter.getEnabledTransitions(net, marking);
      if (modes.size() == 0) {
        System.out.println("Simulation done.");
        return;
      }

      printEnabledTransitions(modes, marking);

      int i = getNextTransition();
      if (i == -1) return;
      if (i >= 0 && i < modes.size()) interpreter.fireTransition(net, marking, modes.get(i));
    }
  }