TreeMultimap<String, Integer> multimap = createPopulate();
    assertThat(multimap.get("foo")).containsExactly(1, 3, 7).inOrder();
    assertThat(multimap.get("google")).containsExactly(2, 6).inOrder();
    assertThat(multimap.get("tree")).containsExactly(0, 4).inOrder();
  }

  public void testOrderedKeySet() {
    TreeMultimap<String, Integer> multimap = createPopulate();