assertThat(immutableGraph).isNotInstanceOf(MutableValueGraph.class);
    assertThat(immutableGraph).isEqualTo(mutableGraph);

    mutableGraph.addNode("B");
    assertThat(immutableGraph).isNotEqualTo(mutableGraph);
  }

  @Test
  public void copyOfImmutableGraph_optimized() {
    Graph<String> graph1 = ImmutableGraph.copyOf(GraphBuilder.directed().<String>build());

   *     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();
  }

    ImmutableBiMap<String, Integer> copy =
        ImmutableBiMap.copyOf(Collections.<String, Integer>emptyMap());
    assertEquals(Collections.<String, Integer>emptyMap(), copy);
    assertSame(copy, ImmutableBiMap.copyOf(copy));
    assertSame(ImmutableBiMap.of(), copy);
  }

  public void testCopyOfSingletonMap() {
    ImmutableBiMap<String, Integer> copy = ImmutableBiMap.copyOf(singletonMap("one", 1));
    assertMapEquals(copy, "one", 1);

      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return ImmutableSet.copyOf(contents);
      }
    },
    ImmutableSortedSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return ImmutableSortedSet.copyOf(contents);
      }
    },
    ContiguousSetImpl {
      @Override

  }

  /**
   * Not supported. Use {@code ImmutableSortedMap.copyOf(ImmutableMap.ofEntries(...))}.
   *
   * @deprecated Use {@code ImmutableSortedMap.copyOf(ImmutableMap.ofEntries(...))}.
   */
  @DoNotCall("ImmutableSortedMap.ofEntries not currently available; use ImmutableSortedMap.copyOf")
  @Deprecated
  @SafeVarargs
  public static <K, V> ImmutableSortedMap<K, V> ofEntries(

  private ListGenerators() {}

  public static class ImmutableListOfGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {
      return ImmutableList.copyOf(elements);
    }
  }

  public static class BuilderAddListGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {

  }

  @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() {

      apply {
        require(tls) { "no cipher suites for cleartext connections" }
        require(cipherSuites.isNotEmpty()) { "At least one cipher suite is required" }

        this.cipherSuites = cipherSuites.copyOf() as Array<String> // Defensive copy.
      }

    fun allEnabledTlsVersions() =
      apply {
        require(tls) { "no TLS versions for cleartext connections" }
        this.tlsVersions = null
      }

    return copyOf(elements);
  }

  public static <E> ImmutableList<E> copyOf(Iterable<? extends E> elements) {
    checkNotNull(elements); // for GWT
    return (elements instanceof Collection)
        ? copyOf((Collection<? extends E>) elements)
        : copyOf(elements.iterator());
  }

  public static <E> ImmutableList<E> copyOf(Iterator<? extends E> elements) {

      return ImmutableSortedSet.copyOf(elements);
    }
  }

  public static class ImmutableSortedSetHeadsetGenerator extends TestStringSortedSetGenerator {
    @Override
    protected SortedSet<String> create(String[] elements) {
      List<String> list = Lists.newArrayList(elements);
      list.add("zzz");
      return ImmutableSortedSet.copyOf(list).headSet("zzy");
    }
  }