class Population {

    public Chromosome[] selectBestKChromosome(int k) {
        if (fitnessCalculatedFlags.cardinality() == chromosomes.length) {
            Chromosome[] cp = Arrays.copyOf(chromosomes, chromosomes.length);
            Arrays.sort(cp);
            return Arrays.copyOfRange(cp, cp.length - k, cp.length);
        }
        return null;
    }

    public  Population(int size);

}