@Test public void intersectInto() { MutableSet<String> set = MultiReaderUnifiedSet.newSetWith("1", "2", "3", "4").asReadUntouchable(); MutableSet<String> intersect = set.intersectInto(UnifiedSet.newSetWith("a", "b", "c", "1"), UnifiedSet.<String>newSet()); Verify.assertSize(1, intersect); Assert.assertEquals(UnifiedSet.newSetWith("1"), intersect); Verify.assertEmpty( set.intersectInto(UnifiedSet.newSetWith("not present"), UnifiedSet.<String>newSet())); }