@After
  public final void validateGraphState() {
    validateGraph(graph);
  }

  static <N> void validateGraph(Graph<N> graph) {
    assertStronglyEquivalent(graph, Graphs.copyOf(graph));
    assertStronglyEquivalent(graph, ImmutableGraph.copyOf(graph));

    String graphString = graph.toString();
    assertThat(graphString).contains("isDirected: " + graph.isDirected());

                this.profiles = profiles != null ? List.copyOf(profiles) : List.of();
                this.activeProfileIds = activeProfileIds != null ? List.copyOf(activeProfileIds) : List.of();
                this.inactiveProfileIds = inactiveProfileIds != null ? List.copyOf(inactiveProfileIds) : List.of();
                this.systemProperties =
                        systemProperties != null ? Map.copyOf(systemProperties) : session.getSystemProperties();

  }

  @Test
  public void copyOfImmutableNetwork_optimized() {
    Network<String, String> network1 =
        ImmutableNetwork.copyOf(NetworkBuilder.directed().<String, String>build());
    Network<String, String> network2 = ImmutableNetwork.copyOf(network1);

    assertThat(network2).isSameInstanceAs(network1);
  }

  @Test
  public void edgesConnecting_directed() {

        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());
    ValueGraph<String, Integer> graph2 = ImmutableValueGraph.copyOf(graph1);

    assertThat(graph2).isSameInstanceAs(graph1);
  }

  @Test
  public void incidentEdgeOrder_stable() {
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());

   *
   * <p><b>Performance note:</b> This method will sometimes recognize that the actual copy operation
   * is unnecessary; for example, {@code copyOf(copyOf(anArrayList))} will copy the data only once.
   * This reduces the expense of habitually making defensive copies at API boundaries. However, the
   * precise conditions for skipping the copy operation are undefined.
   *
   * @throws NullPointerException if any of {@code elements} is null

        for (CoreExtension source : selectedExtensions.values()) {
            context.logger.debug("* " + source.getId() + ": " + formatLocation(source.getLocation("")));
        }
        return List.copyOf(selectedExtensions.values());
    }

    protected String formatLocation(InputLocation location) {
        return location.getSource().getLocation() + ":" + location.getLineNumber();
    }

   * {@link Collection}, this method behaves exactly as {@link #copyOf(Collection)}; otherwise, it
   * behaves exactly as {@code copyOf(elements.iterator()}.
   *
   * @throws NullPointerException if {@code elements} contains a null element
   */
  public static <E> ImmutableList<E> copyOf(Iterable<? extends E> elements) {
    checkNotNull(elements); // TODO(kevinb): is this here only for GWT?

     */
    assertThat(ImmutableLongArray.copyOf(new long[0])).isSameInstanceAs(ImmutableLongArray.of());
  }

  public void testCopyOf_array_nonempty() {
    long[] array = new long[] {0, 1, 3};
    ImmutableLongArray iia = ImmutableLongArray.copyOf(array);
    array[2] = 2;
    assertThat(iia.asList()).containsExactly(0L, 1L, 3L).inOrder();
  }

  public static ImmutableLongArray copyOf(long[] values) {
    return values.length == 0
        ? EMPTY
        : new ImmutableLongArray(Arrays.copyOf(values, values.length));
  }

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableLongArray copyOf(Collection<Long> values) {

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableIntArray copyOf(int[] values) {
    return values.length == 0 ? EMPTY : new ImmutableIntArray(Arrays.copyOf(values, values.length));
  }

  /** Returns an immutable array containing the given values, in order. */
  public static ImmutableIntArray copyOf(Collection<Integer> values) {