@Test
 public void updateValue() {
   MutableMapIterable<Integer, Integer> map = this.newMap();
   Iterate.forEach(
       Interval.oneTo(1000), each -> map.updateValue(each % 10, () -> 0, integer -> integer + 1));
   Assert.assertEquals(Interval.zeroTo(9).toSet(), map.keySet());
   Assert.assertEquals(
       FastList.newList(Collections.nCopies(10, 100)), FastList.newList(map.values()));
 }
 @Test
 public void updateValue_collisions() {
   MutableMapIterable<Integer, Integer> map = this.newMap();
   MutableList<Integer> list = Interval.oneTo(2000).toList();
   Collections.shuffle(list);
   Iterate.forEach(list, each -> map.updateValue(each % 1000, () -> 0, integer -> integer + 1));
   Assert.assertEquals(Interval.zeroTo(999).toSet(), map.keySet());
   Assert.assertEquals(
       HashBag.newBag(map.values()).toStringOfItemToCount(),
       FastList.newList(Collections.nCopies(1000, 2)),
       FastList.newList(map.values()));
 }