class Stats<T extends Number> {

  T[] nums;

​

  // Constructor

  Stats(T[] nums) {

    this.nums = nums;

  }

​

  // Calculate average

  double average() {

    double sum = 0;

    for (T num : nums) {

      sum += num.doubleValue();

    }

    return sum / nums.length;

  }

}

​

public class Main {

  public static void main(String[] args) {

    // Use with Integer

    Integer[] intNums = {10, 20, 30, 40};

    Stats<Integer> intStats = new Stats<>(intNums);

    System.out.println("Integer average: " + intStats.average());

​

    // Use with Double

    Double[] doubleNums = {1.5, 2.5, 3.5};

    Stats<Double> doubleStats = new Stats<>(doubleNums);

    System.out.println("Double average: " + doubleStats.average());

  }

}

​