@Test
public void lastChar_noMatch() {

  assertThat(last('f').in("bar")).isEmpty();
  assertThat(last('f').in("")).isEmpty();
  assertThat(last('f').iterateIn("bar")).isEmpty();
  assertThat(last('f').iterateIn("")).isEmpty();
  assertThat(last("f").in("bar")).isEmpty();
  assertThat(last("f").in("")).isEmpty();
  assertThat(last("f").iterateIn("bar")).isEmpty();
  assertThat(last("f").iterateIn("")).isEmpty();
}