public static <V extends @Nullable Object> ListenableFuture<V> immediateCancelledFuture() {
    ListenableFuture<Object> instance = ImmediateCancelledFuture.INSTANCE;
    if (instance != null) {
      return (ListenableFuture<V>) instance;
    }
    return new ImmediateCancelledFuture<>();
  }

  /**

     * we always return a new instance with a null valueComparator, as we already do if the input is
     * empty or a partial view?
     *
     * Related: Should methods that do accept a comparator (like fromMapEntries, or like this one if
     * we were to choose to *preserve* an input comparator) return not the generic empty of()
     * instance but instead an empty ImmutableSetMultimap instance with the requested

   */
  public static Function<Object, String> toStringFunction() {
    return ToStringFunction.INSTANCE;
  }

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.
      return o.toString();
    }

    @Override

/**
 * Request body for creating related content via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }

/**
 * Request body for creating related query via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }

/**
 * Request body for creating search list via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }

/**
 * Request body for creating access token via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }

 * Request body for creating mapping dictionary via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }

/**
 * Request body for creating group via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }

/**
 * Request body for creating key match via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */
public class CreateBody extends CreateForm {

    /**
     * Creates a new CreateBody instance.
     */
    public CreateBody() {
    }