@Override
  public Collection<V> values() {
    return wrapperMap.values();
  }
@Test
  public void testValues() {
    CharSequenceMap<String> map = CharSequenceMap.create();
    map.put("key1", "value1");
    map.put("key2", "value2");
    assertThat(map.values()).containsAll(ImmutableList.of("value1", "value2"));
  }