}

  /**
   * Returns a hash code, having the same bit length as each of the input hash codes, that combines
   * the information of these hash codes in an ordered fashion. That is, whenever two equal hash
   * codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
   * was computed from the <i>same</i> input hash codes in the <i>same</i> order.
   *

  }

  private static SuccessorsFunction<Character> createDirectedGraph(String... edges) {
    return createGraph(/* directed= */ true, edges);
  }

  private static SuccessorsFunction<Character> createUndirectedGraph(String... edges) {
    return createGraph(/* directed= */ false, edges);
  }

  /**

      LockGraphNode node = new LockGraphNode(getLockName(key));
      nodes.add(node);
      map.put(key, node);
    }
    // Pre-populate all allowedPriorLocks with nodes of smaller ordinal.
    for (int i = 1; i < numKeys; i++) {
      nodes.get(i).checkAcquiredLocks(Policies.THROW, nodes.subList(0, i));
    }
    // Pre-populate all disallowedPriorLocks with nodes of larger ordinal.
    for (int i = 0; i < numKeys - 1; i++) {

    assertStronglyEquivalent(graph, ImmutableValueGraph.copyOf(graph));

    Graph<Integer> asGraph = graph.asGraph();
    AbstractGraphTest.validateGraph(asGraph);
    assertThat(graph.nodes()).isEqualTo(asGraph.nodes());
    assertThat(graph.edges()).isEqualTo(asGraph.edges());
    assertThat(graph.nodeOrder()).isEqualTo(asGraph.nodeOrder());
    assertThat(graph.incidentEdgeOrder()).isEqualTo(asGraph.incidentEdgeOrder());

    // Make sure that hash codes are not computed per-instance.
    assertEqualHashCode(Predicates.not(p1), Predicates.not(p1));

    assertEqualHashCode(Predicates.and(p1, p2), Predicates.and(p1, p2));

    assertEqualHashCode(Predicates.or(p1, p2), Predicates.or(p1, p2));

    // While not a contractual requirement, we'd like the hash codes for ands
    // & ors of the same predicates to not collide.

    return Maps.equalsImpl(this, object);
  }

  @Override
  public int hashCode() {
    // not caching hash code since it could change if map values are mutable
    // in a way that modifies their hash codes
    return entrySet().hashCode();
  }

  @Override
  public String toString() {
    return Maps.toStringImpl(this);
  }

   * {@link Multimap#asMap}.
   *
   * <p>In general, two multimaps with identical key-value mappings may or may not have the same
   * hash codes, depending on the implementation. For example, two {@link SetMultimap} instances
   * with the same key-value mappings will have the same {@code hashCode}, but the {@code hashCode}

  @Override
  @Test
  public void nodes_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<Integer> nodes = graph.nodes();
    UnsupportedOperationException e =
        assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(graph.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test

    for (Integer node : graph.nodes()) {
      new EqualsTester()
          .addEqualityGroup(
              graph.predecessors(node), graph.successors(node), graph.adjacentNodes(node))
          .testEquals();
    }
  }

  @Override
  @Test
  public void nodes_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<Integer> nodes = graph.nodes();
    UnsupportedOperationException e =

    int x = 1000000;
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(6, IntMath.log10(x, mode));
    }
  }

  // Simple test to cover sqrt(0) for all types and all modes.
  @GwtIncompatible // sqrt
  public void testSqrtZeroAlwaysZero() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(0, IntMath.sqrt(0, mode));
    }
  }