private final BaseGraph<N> backingGraph;

  ImmutableGraph(BaseGraph<N> backingGraph) {
    this.backingGraph = backingGraph;
  }

  /** Returns an immutable copy of {@code graph}. */
  public static <N> ImmutableGraph<N> copyOf(Graph<N> graph) {
    return (graph instanceof ImmutableGraph)
        ? (ImmutableGraph<N>) graph
        : new ImmutableGraph<N>(
            new StandardValueGraph<N, Presence>(

   */
  public static <E> ImmutableSortedSet<E> copyOf(
      Comparator<? super E> comparator, Collection<? extends E> elements) {
    return copyOf(comparator, (Iterable<? extends E>) elements);
  }

  /**
   * Returns an immutable sorted set containing the elements of a sorted set, sorted by the same
   * {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which always uses the

      rowBuilder.put(row.getKey(), ImmutableMap.copyOf(row.getValue()));
    }
    this.rowMap = rowBuilder.buildOrThrow();

    ImmutableMap.Builder<C, ImmutableMap<R, V>> columnBuilder =
        new ImmutableMap.Builder<>(columns.size());
    for (Entry<C, Map<R, V>> col : columns.entrySet()) {
      columnBuilder.put(col.getKey(), ImmutableMap.copyOf(col.getValue()));
    }

    COPY_OF_COLLECTION {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys);
      }
    },
    COPY_OF_ITERATOR {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys.iterator());
      }
    },
    BUILDER_ADD_ENTRY_BY_ENTRY {
      @Override

 *       access, and lastly speed of creation.
 *   <li>The {@code copyOf} methods will sometimes recognize that the actual copy operation is
 *       unnecessary; for example, {@code copyOf(copyOf(anArrayList))} should 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.

   * {@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?

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

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

  private ImmutableValueGraph(ValueGraph<N, V> graph) {
    super(ValueGraphBuilder.from(graph), getNodeConnections(graph), graph.edges().size());
  }

  /** Returns an immutable copy of {@code graph}. */
  public static <N, V> ImmutableValueGraph<N, V> copyOf(ValueGraph<N, V> graph) {
    return (graph instanceof ImmutableValueGraph)
        ? (ImmutableValueGraph<N, V>) graph
        : new ImmutableValueGraph<N, V>(graph);
  }

  /**

  @Before
  public void createSets() {
    wrappedSet = new HashSet<>();
    wrappedSet.add(1);
    wrappedSet.add(2);
    wrappedSet.add(3);

    copyOfWrappedSet = ImmutableSet.copyOf(wrappedSet);
    setToTest =
        InvalidatableSet.of(wrappedSet, () -> wrappedSet.contains(1), () -> 1 + "is not present");
  }

  @Test
  @SuppressWarnings("TruthSelfEquals")
  public void testEquals() {

    return ImmutableSortedSet.copyOf(comparator, (Iterable<@NonNull E>) getDelegate());
  }

  /**
   * Returns an {@code ImmutableMultiset} containing all of the elements from this fluent iterable.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code ImmutableMultiset.copyOf(stream.iterator())}, or