}

  public void testFirst_emptySortedSet() {
    SortedSet<String> sortedSet = ImmutableSortedSet.of();
    assertThat(FluentIterable.from(sortedSet).first()).isAbsent();
  }

  public void testFirst_iterable() {
    Set<String> set = ImmutableSet.of("a", "b", "c");
    assertThat(FluentIterable.from(set).first()).hasValue("a");
  }

  public void testFirst_emptyIterable() {
    Set<String> set = new HashSet<>();