thumbnailManager.add(generator);

        Map<String, Object> docMap = new HashMap<>();
        docMap.put("_id", "docid1");

        // Fill the queue
        thumbnailManager.offer(docMap);

        // Try to add another - should succeed (warning logged but still returns true)
        Map<String, Object> docMap2 = new HashMap<>();
        docMap2.put("_id", "docid2");

  }

  static final class ImmediateFailedFuture<V extends @Nullable Object> extends TrustedFuture<V> {
    ImmediateFailedFuture(Throwable thrown) {
      setException(thrown);
    }
  }

  static final class ImmediateCancelledFuture<V extends @Nullable Object> extends TrustedFuture<V> {
    static final @Nullable ImmediateCancelledFuture<Object> INSTANCE =

     *
     * @return Array of arguments
     */
    public Object[] getMethodArgs() {
        return methodArgs;
    }

    /**
     * Returns the array of parameter types.
     *
     * @return Array of parameter types
     */
    public Class<?>[] getParamTypes() {
        return paramTypes;
    }

    private static String getSignature(final Object... methodArgs) {

        setCreatedBy_GreaterThan(createdBy, null);
    }

    public void setCreatedBy_GreaterThan(String createdBy, ConditionOptionCall<RangeQueryBuilder> opLambda) {
        final Object _value = createdBy;
        RangeQueryBuilder builder = regRangeQ("createdBy", ConditionKey.CK_GREATER_THAN, _value);
        if (opLambda != null) {
            opLambda.callback(builder);
        }
    }

  }

  private static void testNetworkMutation(NetworkBuilder<? super Integer, Object> networkBuilder) {
    Random gen = new Random(42); // Fixed seed so test results are deterministic.

    for (int trial = 0; trial < NUM_TRIALS; ++trial) {
      MutableNetwork<Integer, Object> network =
          networkBuilder.allowsParallelEdges(true).allowsSelfLoops(true).build();

    private final TypeToken<?> interfaceType;

    DummyHandler(TypeToken<?> interfaceType) {
      this.interfaceType = interfaceType;
    }

    @Override
    protected @Nullable Object handleInvocation(
        Object proxy, Method method, @Nullable Object[] args) {
      Invokable<?, ?> invokable = interfaceType.method(method);
      ImmutableList<Parameter> params = invokable.getParameters();
      for (int i = 0; i < args.length; i++) {

@GwtCompatible
@Immutable(containerOf = {"R", "C", "V"})
final class SparseImmutableTable<R, C, V> extends RegularImmutableTable<R, C, V> {
  static final ImmutableTable<Object, Object, Object> EMPTY =
      new SparseImmutableTable<>(
          ImmutableList.<Cell<Object, Object, Object>>of(), ImmutableSet.of(), ImmutableSet.of());

  private final ImmutableMap<R, ImmutableMap<C, V>> rowMap;
  private final ImmutableMap<C, ImmutableMap<R, V>> columnMap;

    }

    @Override
    public void acceptAllColumnMap(Entity entity, Map<String, ? extends Object> allColumnMap) {
    }

    @Override
    public Map<String, Object> extractPrimaryKeyMap(Entity entity) {
        return null;
    }

    @Override
    public Map<String, Object> extractAllColumnMap(Entity entity) {
        return null;

 * called.
 */
@NullUnmarked
class LockHeldAssertingSet<E> extends ForwardingSet<E> implements Serializable {
  final Set<E> delegate;
  final Object mutex;

  LockHeldAssertingSet(Set<E> delegate, Object mutex) {
    checkNotNull(mutex);
    this.delegate = delegate;
    this.mutex = mutex;
  }

  @Override
  protected Set<E> delegate() {
    return delegate;
  }

 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
@FunctionalInterface
public interface Supplier<T extends @Nullable Object> extends java.util.function.Supplier<T> {
  /**
   * Retrieves an instance of the appropriate type. The returned object may or may not be a new
   * instance, depending on the implementation.
   *
   * @return an instance of the appropriate type
   */
  @Override