Test.java

package com.eli.testproject;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Test {
	
	public static void main(String[] args) {
		List<Integer> nums = new ArrayList<>();
		List<Box<Integer>> featurizedStream = nums
			.stream()
			.map(x -> new Box(x))
			.collect(Collectors.toList());
	}
	
	private static class Box<T> {
		Box(T item) {}
	}

}