* undocumented and subject to change.
   *
   * <p>Note that if {@code list} is a {@code List<String>}, then {@code ImmutableList.copyOf(list)}
   * returns an {@code ImmutableList<String>} containing each of the strings in {@code list}, while
   * {@code ImmutableList.of(list)} returns an {@code ImmutableList<List<String>>} containing one
   * element (the given list itself).
   *

  @SuppressWarnings("unchecked")
  public static <E> ImmutableList<E> of() {
    return (ImmutableList<E>) RegularImmutableList.EMPTY;
  }

  public static <E> ImmutableList<E> of(E element) {
    return new SingletonImmutableList<E>(checkNotNull(element));
  }

  public static <E> ImmutableList<E> of(E e1, E e2) {
    return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(e1, e2));
  }

   * undocumented and subject to change.
   *
   * <p>Note that if {@code list} is a {@code List<String>}, then {@code ImmutableList.copyOf(list)}
   * returns an {@code ImmutableList<String>} containing each of the strings in {@code list}, while
   * {@code ImmutableList.of(list)} returns an {@code ImmutableList<List<String>>} containing one
   * element (the given list itself).
   *

    Collection<String> c = ImmutableList.of();
    assertSame(c, ImmutableList.copyOf(c));
  }

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

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

    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    map.putInstance(type, array);
    assertEquals(1, map.size());
    assertThat(map.getInstance(type)).asList().containsExactly(array[0]);
  }

  public void testWildcardType() {
    TypeToken<ImmutableList<?>> type = new TypeToken<ImmutableList<?>>() {};
    map.putInstance(type, ImmutableList.of(1));

  private static final ImmutableList<? extends List<Integer>> SAMPLE_INPUTS =
      ImmutableList.of(
          ImmutableList.<Integer>of(),
          ImmutableList.of(1),
          ImmutableList.of(2),
          ImmutableList.of(2, 3),
          ImmutableList.of(1, 2),
          ImmutableList.of(3, 5),
          ImmutableList.of(2, 4),
          ImmutableList.of(1, 2, 3, 5, 6, 8, 9));

  /*

    @Override
    protected List<String> create(String[] elements) {
      return ImmutableList.copyOf(elements);
    }
  }

  public static class BuilderAddListGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {
      ImmutableList.Builder<String> builder = ImmutableList.<String>builder();
      for (String element : elements) {
        builder.add(element);
      }

    assertEquals(type, returnType.getRawType());
    assertEquals(
        ImmutableList.copyOf(type.getTypeParameters()),
        ImmutableList.copyOf(returnType.getActualTypeArguments()));
  }

  public void testConstructor_exceptionTypes() throws Exception {
    assertEquals(
        ImmutableList.of(TypeToken.of(NullPointerException.class)),

  private final transient ImmutableList<List<E>> axes;
  private final transient int[] axesSizeProduct;

  static <E> List<List<E>> create(List<? extends List<? extends E>> lists) {
    ImmutableList.Builder<List<E>> axesBuilder = new ImmutableList.Builder<>(lists.size());
    for (List<? extends E> list : lists) {
      List<E> copy = ImmutableList.copyOf(list);
      if (copy.isEmpty()) {

    runConcurrentlyMutatedTest(elements(1, 2, 3), ops(remove(), remove()), wrap);
  }

  private static ImmutableList<Integer> elements(Integer... elements) {
    return ImmutableList.copyOf(elements);
  }

  private static ImmutableList<ListFrobber> ops(ListFrobber... elements) {
    return ImmutableList.copyOf(elements);
  }

  public void testCopyOf_concurrentlyMutatedList() {