import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
@NullUnmarked
public class TraverserTest {

  /**
   * The undirected graph in the {@link Traverser#breadthFirst(Object)} javadoc:
   *
   * {@snippet :
   * b ---- a ---- d
   * |      |
   * |      |
   * e ---- c ---- f
   * }
   */
  private static final SuccessorsFunction<Character> JAVADOC_GRAPH =

   *     ImmutableSortedMultiset#copyOf(Comparable[])}.</b>
   */
  @DoNotCall("Elements must be Comparable. (Or, pass a Comparator to orderedBy or copyOf.)")
  @Deprecated
  // The usage of "Z" here works around bugs in Javadoc (JDK-8318093) and JDiff.
  public static <Z> ImmutableSortedMultiset<Z> copyOf(Z[] elements) {
    throw new UnsupportedOperationException();
  }

  @J2ktIncompatible private static final long serialVersionUID = 0xdecaf;

      @ParametricNullness
      V output(@ParametricNullness K key, @ParametricNullness V value) {
        return value;
      }
    };
  }

  /*
   * TODO(kevinb): should we copy this javadoc to each concrete class, so that
   * classes like LinkedHashMultimap that need to say something different are
   * still able to {@inheritDoc} all the way from Multimap?
   */

  @Override

  }

  /**
   * Returns a default thread factory used to create new threads.
   *
   * <p>When running on AppEngine with access to <a
   * href="https://cloud.google.com/appengine/docs/standard/java/javadoc/">AppEngine legacy
   * APIs</a>, this method returns {@code ThreadManager.currentRequestThreadFactory()}. Otherwise,
   * it returns {@link Executors#defaultThreadFactory()}.
   *
   * @since 14.0
   */

   *     ImmutableSortedSet#copyOf(Comparable[])}.</b>
   */
  @DoNotCall("Pass parameters of type Comparable")
  @Deprecated
  // The usage of "Z" here works around bugs in Javadoc (JDK-8318093) and JDiff.
  public static <Z> ImmutableSortedSet<Z> copyOf(Z[] elements) {
    throw new UnsupportedOperationException();
  }

        comparator, keyFunction, valueFunction, mergeFunction);
  }

  /*
   * TODO(kevinb): Confirm that ImmutableSortedMap is faster to construct and
   * uses less memory than TreeMap; then say so in the class Javadoc.
   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =

        comparator, keyFunction, valueFunction, mergeFunction);
  }

  /*
   * TODO(kevinb): Confirm that ImmutableSortedMap is faster to construct and
   * uses less memory than TreeMap; then say so in the class Javadoc.
   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =

   * java.util.stream.Stream#filter}. This method is not being deprecated, but we gently encourage
   * you to migrate to streams.
   */
  // TODO(kevinb): how to omit that last sentence when building GWT javadoc?
  public static <E extends @Nullable Object> Set<E> filter(
      Set<E> unfiltered, Predicate<? super E> predicate) {
    if (unfiltered instanceof SortedSet) {
      return filter((SortedSet<E>) unfiltered, predicate);

   * java.util.stream.Stream#filter}. This method is not being deprecated, but we gently encourage
   * you to migrate to streams.
   */
  // TODO(kevinb): how to omit that last sentence when building GWT javadoc?
  public static <E extends @Nullable Object> Set<E> filter(
      Set<E> unfiltered, Predicate<? super E> predicate) {
    if (unfiltered instanceof SortedSet) {
      return filter((SortedSet<E>) unfiltered, predicate);

            The classifier of the dependency. It is appended to
            the filename after the version. This allows:
            <ul>
            <li>referring to attached artifact, for example {@code sources} and {@code javadoc}:
            see <a href="../maven-core/artifact-handlers.html">default artifact handlers</a> for a list,</li>
            <li>distinguishing two artifacts
            that belong to the same POM but were built differently.