CombinationGenerator

gistfile1.java

@Test
public void test () {
		
	Set<Integer> test = Sets.newHashSet(1, 2, 3, 4);
		
	Set<Set<Integer>> elements = Sets.powerSet(test);
	
	List<Integer> test2 = elements.stream().filter(p -> p.size() == 3).collect(Collectors.toList());
	
	System.out.println(test2);

//	[[1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]]
}