String[] array = new String[0];
    Multiset<String> multiset = ImmutableMultiset.copyOf(array);
    assertTrue(multiset.isEmpty());
  }

  public void testCreation_arrayOfOneElement() {
    String[] array = new String[] {"a"};
    Multiset<String> multiset = ImmutableMultiset.copyOf(array);
    assertEquals(HashMultiset.create(asList("a")), multiset);
  }

  protected <E extends Comparable<? super E>> SortedSet<E> copyOf(E[] elements) {
    return ImmutableSortedSet.copyOf(elements);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> copyOf(
      Collection<? extends E> elements) {
    return ImmutableSortedSet.copyOf(elements);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> copyOf(Iterable<? extends E> elements) {

    assertEquals(Collections.<String>emptySet(), copyOf(c));
    assertSame(c, copyOf(c));
  }

  public void testCopyOf_shortcut_singleton() {
    Collection<String> c = of("a");
    assertEquals(singleton("a"), copyOf(c));
    assertSame(c, copyOf(c));
  }

  public void testCopyOf_shortcut_sameType() {
    Collection<String> c = of("a", "b", "c");
    assertSame(c, copyOf(c));
  }

    String[] array = new String[0];
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(array);
    assertTrue(multiset.isEmpty());
  }

  public void testCreation_arrayOfOneElement() {
    String[] array = new String[] {"a"};
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(array);
    assertEquals(HashMultiset.create(asList("a")), multiset);
  }

    }

    if (map.isEmpty()) {
      return of();
    }

    ImmutableMap<K, V> immutableMap = ImmutableMap.copyOf(map);
    return new RegularImmutableBiMap<K, V>(immutableMap);
  }

  public static <K, V> ImmutableBiMap<K, V> copyOf(
      Iterable<? extends Entry<? extends K, ? extends V>> entries) {
    return new Builder<K, V>().putAll(entries).build();
  }

  ImmutableBiMap(Map<K, V> delegate) {

    assertEquals(asList("a", "b", "a"), list);
    List<String> mutableList = asList("a", "b");
    list = ImmutableList.copyOf(mutableList);
    mutableList.set(0, "c");
    assertEquals(asList("a", "b"), list);
  }

  public void testCopyOf_collectionContainingNull() {
    Collection<@Nullable String> c = MinimalCollection.of("a", null, "b");

      @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

    POSITIVE_INTEGER_CANDIDATES = intValues.build();
    NEGATIVE_INTEGER_CANDIDATES =
        ImmutableList.copyOf(
            Iterables.concat(
                Iterables.transform(POSITIVE_INTEGER_CANDIDATES, NEGATE_INT),
                ImmutableList.of(Integer.MIN_VALUE)));
    NONZERO_INTEGER_CANDIDATES =
        ImmutableList.copyOf(
            Iterables.concat(POSITIVE_INTEGER_CANDIDATES, NEGATIVE_INTEGER_CANDIDATES));

    POSITIVE_INTEGER_CANDIDATES = intValues.build();
    NEGATIVE_INTEGER_CANDIDATES =
        ImmutableList.copyOf(
            Iterables.concat(
                Iterables.transform(POSITIVE_INTEGER_CANDIDATES, NEGATE_INT),
                ImmutableList.of(Integer.MIN_VALUE)));
    NONZERO_INTEGER_CANDIDATES =
        ImmutableList.copyOf(
            Iterables.concat(POSITIVE_INTEGER_CANDIDATES, NEGATIVE_INTEGER_CANDIDATES));

    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());