public void isNotIn(@Nullable Iterable<?> iterable) {
    checkNotNull(iterable);
    if (Iterables.contains(iterable, actual)) {
      failWithActual("expected not to be any of", iterable);
    }
  }
@Test
  public void isNotInEmpty() {
    assertThat("b").isNotIn(ImmutableList.<String>of());
  }