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<>();
    assertThat(FluentIterable.from(set).first()).isAbsent();
  }

  public void testLast_list() {

    assertThat(ArbitraryInstances.get(Splitter.class).split("a,b")).isNotNull();
    assertThat(ArbitraryInstances.get(com.google.common.base.Optional.class)).isAbsent();
    ArbitraryInstances.get(Stopwatch.class).start();
    assertThat(ArbitraryInstances.get(Ticker.class)).isNotNull();
    assertFreshInstanceReturned(Random.class);
    assertEquals(

    assertThat(ArbitraryInstances.get(Splitter.class).split("a,b")).isNotNull();
    assertThat(ArbitraryInstances.get(com.google.common.base.Optional.class)).isAbsent();
    ArbitraryInstances.get(Stopwatch.class).start();
    assertThat(ArbitraryInstances.get(Ticker.class)).isNotNull();
    assertFreshInstanceReturned(Random.class);
    assertEquals(

    assertThat(tryFind(list, equalTo("pants"))).hasValue("pants");
    assertThat(tryFind(list, Predicates.alwaysTrue())).hasValue("cool");
    assertThat(tryFind(list, Predicates.alwaysFalse())).isAbsent();
    assertCanIterateAgain(list);
  }

  private static class TypeA {}

  private interface TypeB {}

  private static class HasBoth extends TypeA implements TypeB {}