// Identical valid surrogate pairs.
    assertEquals(
        "abc\uD8AB\uDCAB", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz"));
    // Differing valid surrogate pairs.
    assertEquals("abc", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCACxyz"));
    // One invalid pair.

    }
    assertEquals(expected, builder.toString());
  }

  static final CharSource BROKEN_READ_SOURCE = new TestCharSource("ABC", READ_THROWS);
  static final CharSource BROKEN_CLOSE_SOURCE = new TestCharSource("ABC", CLOSE_THROWS);
  static final CharSource BROKEN_OPEN_SOURCE = new TestCharSource("ABC", OPEN_THROWS);
  static final CharSink BROKEN_WRITE_SINK = new TestCharSink(WRITE_THROWS);

        .expect("A", "B", "C", "D", "E");
  }

  public void testFlatMap() {
    SpliteratorTester.of(
            () ->
                CollectSpliterators.flatMap(
                    Arrays.spliterator(new String[] {"abc", "", "de", "f", "g", ""}),
                    (String str) -> Lists.charactersOf(str).spliterator(),
                    Spliterator.SIZED | Spliterator.DISTINCT | Spliterator.NONNULL,
                    7))

    // Identical valid surrogate pairs.
    assertEquals(
        "abc\uD8AB\uDCAB", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz"));
    // Differing valid surrogate pairs.
    assertEquals("abc", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCACxyz"));
    // One invalid pair.

            + "field1=This is string., field2=[abc, def, ghi], field3={abc=1, def=2, ghi=3}}";

    assertEquals(expected, toTest);
  }

  public void testToStringLenient_complexFields() {
    Map<String, Integer> map =
        ImmutableMap.<String, Integer>builder().put("abc", 1).put("def", 2).put("ghi", 3).build();
    String toTest =
        MoreObjects.toStringHelper(new TestClass())
            .add("field1", "This is string.")

    assertEquals(java.util.Optional.of("abc"), Optional.toJavaUtil(Optional.of("abc")));
  }

  public void testToJavaUtil_instance() {
    assertEquals(java.util.Optional.empty(), Optional.absent().toJavaUtil());
    assertEquals(java.util.Optional.of("abc"), Optional.of("abc").toJavaUtil());
  }

  public void testFromJavaUtil() {
    assertNull(Optional.fromJavaUtil(null));

/**
 * Unit test for {@link FakeTimeLimiter}.
 *
 * @author Jens Nyman
 */
public class FakeTimeLimiterTest extends TestCase {

  private static final int DELAY_MS = 50;
  private static final String RETURN_VALUE = "abc";

  private TimeLimiter timeLimiter;

  @Override
  protected void setUp() throws Exception {
    super.setUp();
    timeLimiter = new FakeTimeLimiter();
  }

  }

  @SuppressWarnings("unchecked") // functor classes have no type parameters
  public void testGet_functors() {
    assertEquals(0, ArbitraryInstances.get(Comparator.class).compare("abc", 123));
    assertTrue(ArbitraryInstances.get(Predicate.class).apply("abc"));
    assertTrue(ArbitraryInstances.get(Equivalence.class).equivalent(1, 1));
    assertFalse(ArbitraryInstances.get(Equivalence.class).equivalent(1, 2));
  }

  }

  public void testEmptiesFirst() {
    Optional<String> empty = Optional.empty();
    Optional<String> abc = Optional.of("abc");
    Optional<String> z = Optional.of("z");

    Comparator<Optional<String>> comparator = Comparators.emptiesFirst(comparing(String::length));
    Helpers.testComparator(comparator, empty, z, abc);

    // Just demonstrate that no explicit type parameter is required

    }
    assertEquals(expected, builder.toString());
  }

  static final CharSource BROKEN_READ_SOURCE = new TestCharSource("ABC", READ_THROWS);
  static final CharSource BROKEN_CLOSE_SOURCE = new TestCharSource("ABC", CLOSE_THROWS);
  static final CharSource BROKEN_OPEN_SOURCE = new TestCharSource("ABC", OPEN_THROWS);
  static final CharSink BROKEN_WRITE_SINK = new TestCharSink(WRITE_THROWS);