assertThat(ArbitraryInstances.get(String[].class)).isEmpty();
  }

  public void testGet_enum() {
    assertNull(ArbitraryInstances.get(EmptyEnum.class));
    assertEquals(Direction.UP, ArbitraryInstances.get(Direction.class));
  }

  public void testGet_interface() {
    assertNull(ArbitraryInstances.get(SomeInterface.class));
  }

  public void testGet_runnable() {

    this.size = 0;
    this.mask = tableSize - 1;
    this.modCount = 0;
  }

  /**
   * Finds and removes {@code entry} from the bucket linked lists in both the key-to-value direction
   * and the value-to-key direction.
   */
  private void delete(BiEntry<K, V> entry) {
    int keyBucket = entry.keyHash & mask;
    BiEntry<K, V> prevBucketEntry = null;
    for (BiEntry<K, V> bucketEntry = hashTableKToV[keyBucket];

   * include a {@link Builder.DuplicateKey} in case duplicate keys are not allowed now or will not
   * be allowed on a later {@link Builder#buildOrThrow()} call.
   *
   * @param keyOffset 1 if this is the reverse direction of a BiMap, 0 otherwise.
   * @return an {@code Object} that is a {@code byte[]}, {@code short[]}, or {@code int[]}, the
   *     smallest possible to fit {@code tableSize}; or an {@code Object[]} where [0] is one of

    putEdge(N1, N2);
    assertThat(graph.predecessors(N2)).containsExactly(N1);
    // Edge direction handled correctly
    assertThat(graph.predecessors(N1)).isEmpty();
  }

  @Test
  public void successors_oneEdge() {
    putEdge(N1, N2);
    assertThat(graph.successors(N1)).containsExactly(N2);
    // Edge direction handled correctly
    assertThat(graph.successors(N2)).isEmpty();
  }

  @Test

 * java.util.function.Predicate} is expected, use the method reference {@code
 * guavaPredicate::apply}. For the other direction, use {@code javaUtilPredicate::test}. A future
 * version of this interface will be made to <i>extend</i> {@code java.util.function.Predicate}, so
 * that conversion will be necessary in only one direction. At that time, this interface will be
 * officially discouraged.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */

 * </ul>
 *
 * <p>Using a converter:
 *
 * <ul>
 *   <li>Convert one instance in the "forward" direction using {@code converter.convert(a)}.
 *   <li>Convert multiple instances "forward" using {@code converter.convertAll(as)}.
 *   <li>Convert in the "backward" direction using {@code converter.reverse().convert(b)} or {@code
 *       converter.reverse().convertAll(bs)}.

  @CanIgnoreReturnValue
  @ParametricNullness
  V checkValue(@ParametricNullness V value) {
    return value;
  }

  /**
   * Specifies the delegate maps going in each direction. Called by the constructor and by
   * subclasses during deserialization.
   */
  void setDelegates(Map<K, V> forward, Map<V, K> backward) {
    checkState(delegate == null);
    checkState(inverse == null);

    // Passed nodes should be in the correct edge direction, first is the
    // source node and the second is the target node
    assertThat(network.edgesConnecting(N2, N1)).isEmpty();
  }

  @Test
  public void inEdges_oneEdge() {
    addEdge(N1, N2, E12);
    assertThat(network.inEdges(N2)).containsExactly(E12);
    // Edge direction handled correctly
    assertThat(network.inEdges(N1)).isEmpty();
  }

    putEdge(N1, N2);
    assertThat(graph.predecessors(N2)).containsExactly(N1);
    // Edge direction handled correctly
    assertThat(graph.predecessors(N1)).isEmpty();
  }

  @Test
  public void successors_oneEdge() {
    putEdge(N1, N2);
    assertThat(graph.successors(N1)).containsExactly(N2);
    // Edge direction handled correctly
    assertThat(graph.successors(N2)).isEmpty();
  }

  @Test

  @Override
  Set<N> adjacentNodes(N node);

  /**
   * Returns a live view of all nodes in this graph adjacent to {@code node} which can be reached by
   * traversing {@code node}'s incoming edges <i>against</i> the direction (if any) of the edge.
   *
   * <p>In an undirected graph, this is equivalent to {@link #adjacentNodes(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the `Set` returned by