docs: public static void main(String[] args) {
      Random random = new Random();
      int length = 100;
      double[] A = new double[length];
      double[] B = new double[length];
      double aAvg = 70.0;
      double bAvg = 70.5;
      for (int i = 0; i < length; i++) {
        A[i] = aAvg + random.nextGaussian();
        B[i] = bAvg + random.nextGaussian();
      }
      System.out.println("A has length " + A.length + " and mean " + mean(A));
      System.out.println("B has length " + B.length + " and mean " + mean(B));
      for (int t = 0; t < 10; t++) {
        System.out.println("p-value: " + sigLevelByApproxRand(A, B));
      }
    }