async.cancel(true);
    assertTrue(inner.isCancelled());
    assertTrue(inner.wasInterrupted());
    assertThrows(CancellationException.class, inner::get);
  }

  public void testCancel_resultCancelsInner() throws Exception {
    SettableFuture<Object> async = SettableFuture.create();
    SettableFuture<Object> inner = SettableFuture.create();
    async.setFuture(inner);
    async.cancel(false);

    async.cancel(true);
    assertTrue(inner.isCancelled());
    assertTrue(inner.wasInterrupted());
    assertThrows(CancellationException.class, inner::get);
  }

  public void testCancel_resultCancelsInner() throws Exception {
    SettableFuture<Object> async = SettableFuture.create();
    SettableFuture<Object> inner = SettableFuture.create();
    async.setFuture(inner);
    async.cancel(false);

    assertEquals(mapping.t, mapping.selfMapping().getToType());
  }

  private static class ParameterizedOuter<T> {
    @Keep public Inner field;

    @SuppressWarnings("ClassCanBeStatic") // We want to test an inner class.
    class Inner {}
  }

  public void testInnerClassWithParameterizedOwner() throws Exception {
    Type fieldType = ParameterizedOuter.class.getField("field").getGenericType();

    assertEquals(mapping.t, mapping.selfMapping().getToType());
  }

  private static class ParameterizedOuter<T> {
    @Keep public Inner field;

    @SuppressWarnings("ClassCanBeStatic") // We want to test an inner class.
    class Inner {}
  }

  public void testInnerClassWithParameterizedOwner() throws Exception {
    Type fieldType = ParameterizedOuter.class.getField("field").getGenericType();

    @SuppressWarnings("unchecked")
    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;

public class SynchronizedMapTest extends TestCase {
  public final Object mutex = new Object[0]; // something Serializable

  protected <K, V> Map<K, V> create() {
    TestMap<K, V> inner = new TestMap<>(new HashMap<K, V>(), mutex);
    Map<K, V> outer = Synchronized.map(inner, mutex);
    return outer;
  }

  static class TestMap<K, V> extends ForwardingMap<K, V> implements Serializable {
    public final Object mutex;

    assertFalse(delegate.isOverridable());
    assertFalse(delegate.isVarArgs());
  }

  @SuppressWarnings("ClassCanBeStatic") // We want to test an inner class.
  private class InnerWithDefaultConstructor {
    class NestedInner {}
  }

  public void testInnerClassDefaultConstructor() {

    assertTrue(
        Visibility.PACKAGE.isVisible(VisibilityMethods.class.getDeclaredMethod("publicMethod")));
  }

  @SuppressWarnings("ClassCanBeStatic") // We want to test an inner class.
  private class Inner {
    @Keep
    public Inner(String s) {
      checkNotNull(s);
    }
  }

  public void testNonStaticInnerClass() {
    IllegalArgumentException expected =
        assertThrows(

        // NEVER
        "AssignmentExpression", // Not using it is more a matter of taste.
        "EffectivelyPrivate", // It is still useful to distinguish between public interface and implementation details of inner classes even though it isn't enforced.
        "InjectOnConstructorOfAbstractClass", // We use abstract injection as a pattern
        "InlineMeSuggester", // Only suppression seems to actually "fix" this, so make it global

                .expiry(0) // Should not change
                .expiry(3000L);

        assertSame(purgeThumbnailJob, result);
        assertEquals(3000L, purgeThumbnailJob.getExpiry());
    }

    // Inner class for mock ThumbnailManager
    private static class MockThumbnailManager extends ThumbnailManager {
        private long purgeCallCount = 0;
        private long purgeExpiry = 0;