Set<String> keySet = map.keySet();
    assertTrue(keySet instanceof SynchronizedSet);
    assertSame(mutex, ((SynchronizedSet<?>) keySet).mutex);
  }

  public void testValues() {
    Map<String, Integer> map = create();
    Collection<Integer> values = map.values();
    assertTrue(values instanceof SynchronizedCollection);
    assertSame(mutex, ((SynchronizedCollection<?>) values).mutex);
  }

  public void testEntrySet() {

    assertEquals(Collections.<String, Integer>emptyMap(), copy);
    assertSame(copy, ImmutableBiMap.copyOf(copy));
    assertSame(ImmutableBiMap.of(), copy);
  }

  public void testCopyOfSingletonMap() {
    ImmutableBiMap<String, Integer> copy = ImmutableBiMap.copyOf(singletonMap("one", 1));
    assertMapEquals(copy, "one", 1);
    assertSame(copy, ImmutableBiMap.copyOf(copy));
  }

  public void testCopyOf() {

        assertThrows(UncheckedExecutionException.class, () -> cache.getUnchecked(new Object()));
    assertThat(expected).hasCauseThat().isEqualTo(cause);

    Object newValue = new Object();
    valueRef.set(newValue);
    assertSame(newValue, cache.getUnchecked(new Object()));
  }

  public void testGetUnchecked_unchecked() {
    final RuntimeException cause = new RuntimeException();
    final AtomicReference<Object> valueRef = new AtomicReference<>();

    String s1 = "foo";
    String s2 = MoreObjects.firstNonNull(s1, "bar");
    assertSame(s1, s2);

    Long n1 = 42L;
    Long n2 = MoreObjects.firstNonNull(null, n1);
    assertSame(n1, n2);

    Boolean b1 = true;
    Boolean b2 = MoreObjects.firstNonNull(b1, null);
    assertSame(b1, b2);
  }

  public void testFirstNonNull_throwsNullPointerException() {

    String s1 = "foo";
    String s2 = MoreObjects.firstNonNull(s1, "bar");
    assertSame(s1, s2);

    Long n1 = 42L;
    Long n2 = MoreObjects.firstNonNull(null, n1);
    assertSame(n1, n2);

    Boolean b1 = true;
    Boolean b2 = MoreObjects.firstNonNull(b1, null);
    assertSame(b1, b2);
  }

  public void testFirstNonNull_throwsNullPointerException() {

    SomeCheckedException exception = new SomeCheckedException();
    assertSame(exception, getRootCause(exception));
  }

  public void testGetRootCause_singleWrapped() {
    SomeCheckedException cause = new SomeCheckedException();
    SomeChainingException exception = new SomeChainingException(cause);
    assertSame(cause, getRootCause(exception));
  }

  public void testGetRootCause_doubleWrapped() {

  }

  public void testSerialization() {
    assertSame(
        Funnels.byteArrayFunnel(), SerializableTester.reserialize(Funnels.byteArrayFunnel()));
    assertSame(Funnels.integerFunnel(), SerializableTester.reserialize(Funnels.integerFunnel()));
    assertSame(Funnels.longFunnel(), SerializableTester.reserialize(Funnels.longFunnel()));
    assertSame(
        Funnels.unencodedCharsFunnel(),

    assertNotSame(mod, unmod);
    assertSame(unmod, Multimaps.unmodifiableListMultimap(unmod));
    ImmutableListMultimap<String, Integer> immutable =
        ImmutableListMultimap.of("a", 1, "b", 2, "a", 3);
    assertSame(immutable, Multimaps.unmodifiableListMultimap(immutable));
    assertSame(
        immutable, Multimaps.unmodifiableListMultimap((ListMultimap<String, Integer>) immutable));

    assertEquals(pair.forward, copy.forward);
    assertEquals(pair.backward, copy.backward);
    assertSame(copy.backward, copy.forward.inverse());
    assertSame(copy.forward, copy.backward.inverse());
  }

  private static class BiMapPair<K, V> implements Serializable {
    final BiMap<K, V> forward;
    final BiMap<V, K> backward;

    BiMapPair(BiMap<K, V> original) {
      this.forward = original;

    Collection<String> c = ImmutableList.of();
    assertSame(c, ImmutableList.copyOf(c));
  }

  public void testCopyOf_shortcut_singleton() {
    Collection<String> c = ImmutableList.of("a");
    assertSame(c, ImmutableList.copyOf(c));
  }

  public void testCopyOf_shortcut_immutableList() {
    Collection<String> c = ImmutableList.of("a", "b", "c");
    assertSame(c, ImmutableList.copyOf(c));
  }