@Test
 public void forEachWith() {
   MutableBag<String> result = Bags.mutable.of();
   ImmutableBag<String> bag = this.newBag();
   bag.forEachWith(
       (argument1, argument2) -> {
         result.add(argument1 + argument2);
       },
       "");
   Assert.assertEquals(bag, result);
 }