protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();
    Queue<String> outer = Synchronized.queue(inner, null);
    inner.mutex = outer;
    outer.add("foo"); // necessary because we try to remove elements later on
    return outer;
  }

  private static final class TestQueue<E> implements Queue<E> {
    private final Queue<E> delegate = Lists.newLinkedList();

                TestSet<String> inner = new TestSet<>(new HashSet<String>(), null);
                Set<String> outer = Synchronized.set(inner, null);
                inner.mutex = outer;
                Collections.addAll(outer, elements);
                return outer;
              }
            })
        .named("Synchronized.set")
        .withFeatures(
            CollectionFeature.GENERAL_PURPOSE,

  }

  public void testConverter_nullConversions() {
    for (CaseFormat outer : CaseFormat.values()) {
      for (CaseFormat inner : CaseFormat.values()) {
        assertNull(outer.converterTo(inner).convert(null));
        assertNull(outer.converterTo(inner).reverse().convert(null));
      }
    }
  }

  public void testConverter_toString() {
    assertEquals(

    NavigableMap<K, V> innermost =
        new SafeTreeMap<>((Comparator<? super K>) Ordering.natural().nullsFirst());
    TestMap<K, V> inner = new TestMap<>(innermost, mutex);
    NavigableMap<K, V> outer = Synchronized.navigableMap(inner, mutex);
    return outer;
  }

  static class TestEntry<K, V> extends ForwardingMapEntry<K, V> implements Serializable {
    private final Entry<K, V> delegate;
    private final Object mutex;

public class SynchronizedDequeTest extends TestCase {

  protected Deque<String> create() {
    TestDeque<String> inner = new TestDeque<>();
    Deque<String> outer = Synchronized.deque(inner, inner.mutex);
    outer.add("foo"); // necessary because we try to remove elements later on
    return outer;
  }

  private static final class TestDeque<E> implements Deque<E> {
    private final Deque<E> delegate = Lists.newLinkedList();

    return suite;
  }

  @Override
  protected <K, V> BiMap<K, V> create() {
    TestBiMap<K, V> inner = new TestBiMap<>(HashBiMap.<K, V>create(), mutex);
    BiMap<K, V> outer = Synchronized.biMap(inner, mutex);
    return outer;
  }

  public static final class SynchronizedHashBiMapGenerator extends TestStringBiMapGenerator {
    @Override
    protected BiMap<String, String> create(Entry<String, String>[] entries) {

  }

  public void testConverter_nullConversions() {
    for (CaseFormat outer : CaseFormat.values()) {
      for (CaseFormat inner : CaseFormat.values()) {
        assertNull(outer.converterTo(inner).convert(null));
        assertNull(outer.converterTo(inner).reverse().convert(null));
      }
    }
  }

  public void testConverter_toString() {
    assertEquals(

  protected <E> NavigableSet<E> create() {
    TestSet<E> inner =
        new TestSet<>(new TreeSet<E>((Comparator<E>) Ordering.natural().nullsFirst()), null);
    NavigableSet<E> outer = Synchronized.navigableSet(inner, null);
    inner.mutex = outer;
    return outer;
  }

  static class TestSet<E> extends SynchronizedSetTest.TestSet<E> implements NavigableSet<E> {

    TestSet(NavigableSet<E> delegate, @Nullable Object mutex) {

    NavigableMap<K, V> innermost =
        new SafeTreeMap<>((Comparator<? super K>) Ordering.natural().nullsFirst());
    TestMap<K, V> inner = new TestMap<>(innermost, mutex);
    NavigableMap<K, V> outer = Synchronized.navigableMap(inner, mutex);
    return outer;
  }

  static class TestEntry<K, V> extends ForwardingMapEntry<K, V> implements Serializable {
    private final Entry<K, V> delegate;
    private final Object mutex;

    assertEquals("FooBar{}", toTest);
  }

  @GwtIncompatible // Class names are obfuscated in GWT
  public void testToStringHelper_localInnerClass() {
    // Local inner classes have names ending like "Outer.$1Inner"
    class LocalInnerClass {}
    String toTest = MoreObjects.toStringHelper(new LocalInnerClass()).toString();
    assertEquals("LocalInnerClass{}", toTest);
  }