How to find the triplet numbers from an array whose sum is divisible by 9 using stream

import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class Divby9TripletsUsingStreams {

	public static List<List<Integer>> divBy9Triplets(int[] numArr, Predicate<Integer> div9) {

		System.out.println("The hardcoded array of integers given below");
		Arrays.stream(numArr).forEach(x -> System.out.print(x + " "));
		System.out.println("\nThe triplets of numbers which are divisible by 9");
		/*
		 * Using the nested IntStream (3 levels), flatMap, and filter return list
		 * objects as triplets, the criteria is sum of each triplet is divisible by 9
		 */
		return IntStream.range(0, numArr.length).boxed()
				.flatMap(i -> IntStream.range(i + 1, numArr.length).boxed()
						.flatMap(j -> IntStream.range(j + 1, numArr.length)
								.filter(k -> div9.test(numArr[i] + numArr[j] + numArr[k]))
								.mapToObj(k -> Arrays.asList(numArr[i], numArr[j], numArr[k]))))
				.collect(Collectors.toList());

	}

	public static void main(String[] args) {

		int[] intArr = { 14, 20, 7, 16, 25, 34, 4 };
		System.out.println("OUTPUT:");

		// Calling the function divby9 which computes the sum of triplets divisible by 9
		System.out.println(divBy9Triplets(intArr, (i) -> i % 9 == 0));
	}
}