code: @Override
      public double[][] selectParents() {
          double[][] parents = new double[2][];
  
          int parent1Idx = rng.nextInt(population.size());
          int parent2Idx;
          do {
              parent2Idx = rng.nextInt(population.size());
          } while (parent1Idx == parent2Idx);
  
          parents[0] = population.get(parent1Idx).getGenes();
          parents[1] = population.get(parent2Idx).getGenes();
  
          return parents;
      }
docs: Selects two random parents
  
  @return An array of parents genes. The outer array are the parents, and the inner array are the genes.