private static Solver referencePropagation(Modeler modeler, int nbVar, int[][] domains, THashMap<int[], IntVar> map, Object parameters) {
Solver ref = modeler.model(nbVar, domains, map, parameters);
ref.getEnvironment().worldPush();
try {
ref.propagate();
} catch (ContradictionException e) {
LoggerFactory.getLogger("test").info("Pas de solution pour ce probleme => rien a tester !");
return null;
} catch (Exception e) {
File f = new File("SOLVER_ERROR.ser");