for (int i = 0; i < 1000; i++) {
            Schedule candidate = mergeTwoTracksInOne(scheduleCurrent);
            if(candidate.isInvalid()) {
                continue;
            }
            neighbour = candidate;
           // while ((neighbour = mergeTwoTracksInOne(scheduleCurrent)).isInvalid()) ;
            double newFitness = neighbour.fitness();
            if (newFitness >= this.scheduleBest.fitness()) {
                scheduleBest = neighbour;
            scheduleCurrent = neighbour;
                         System.out.println(scheduleCurrent.fitness());
            }
       }