*   }
 * };
 * LoadingCache<Key, Graph> cache = CacheBuilder.newBuilder().build(loader);
 * }</pre>
 *
 * <p>Since this example doesn't support reloading or bulk loading, if you're able to use lambda
 * expressions it can be specified even more easily:
 *
 * <pre>{@code
 * CacheLoader<Key, Graph> loader = CacheLoader.from(key -> createExpensiveGraph(key));
 * }</pre>
 *
 * @author Charles Fry
 * @since 10.0

 * appropriate primitive specialization such as {@code IntPredicate}) instead whenever possible.
 * Otherwise, at least reduce <i>explicit</i> dependencies on this type by using lambda expressions
 * or method references instead of classes, leaving your code easier to migrate in the future.
 *
 * <p>The {@link Predicates} class provides common predicates and related utilities.
 *

 * appropriate primitive specialization such as {@code IntPredicate}) instead whenever possible.
 * Otherwise, at least reduce <i>explicit</i> dependencies on this type by using lambda expressions
 * or method references instead of classes, leaving your code easier to migrate in the future.
 *
 * <p>To use a reference of this type (say, named {@code guavaPredicate}) in a context where {@code

   * instead.
   *
   * <p>Unfortunately, the method reference {@code Optional::toJavaUtil} will not work, because it
   * could refer to either the static or instance version of this method. Write out the lambda
   * expression {@code o -> Optional.toJavaUtil(o)} instead.
   *
   * @since 21.0
   */
  @CheckForNull
  public static <T> java.util.Optional<T> toJavaUtil(@CheckForNull Optional<T> googleOptional) {

 *       the {@code Converter} type using a mocking framework.
 *   <li>Extend this class and implement its {@link #doForward} and {@link #doBackward} methods.
 *   <li><b>Java 8+ users:</b> you may prefer to pass two lambda expressions or method references to
 *       the {@link #from from} factory method.
 * </ul>
 *
 * <p>Using a converter:
 *
 * <ul>

   *   <li>clearing weak references to unreachable referents
   *   <li>enqueuing weak references to unreachable referents in their reference queue
   * </ul>
   */
  @DoNotMock("Implement with a lambda")
  public interface FinalizationPredicate {
    boolean isDone();
  }

  /**
   * Waits until the given weak reference is cleared, invoking the garbage collector as necessary to

    }

    @Override
    public String toString() {
      return "Functions.toStringFunction()";
    }
  }

  /**
   * Returns the identity function.
   *
   * <p><b>Discouraged:</b> Prefer using a lambda like {@code v -> v}, which is shorter and often
   * more readable.
   */
  // implementation is "fully variant"; E has become a "pass-through" type
  @SuppressWarnings("unchecked")

  }

  /**
   * Returns a cache loader that uses {@code function} to load keys, without supporting either
   * reloading or bulk loading. This allows creating a cache loader using a lambda expression.
   *
   * <p>The returned object is serializable if {@code function} is serializable.
   *
   * @param function the function to be used for loading values; must never return {@code null}

 * </ul>
 *
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @since 23.1
 */
@Beta
@DoNotMock(
    "Call forGraph or forTree, passing a lambda or a Graph with the desired edges (built with"
        + " GraphBuilder)")
@ElementTypesAreNonnullByDefault
public abstract class Traverser<N> {
  private final SuccessorsFunction<N> successorFunction;

  }

  public <T> void testVariableTypeTokenNotAllowed() {
    /*
     * We'd use assertThrows here, but that causes no exception to be thrown under Java 8,
     * presumably because the ThrowingRunnable lambda triggers some kind of bug in Java 8's
     * reflection implementation.
     */
    try {
      new TypeToken<T>() {};
      fail();
    } catch (IllegalStateException expected) {
    }
  }