* 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 e1) {
    return new SingletonImmutableList<E>(checkNotNull(e1));
  }

  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("a", "b", "c");
    assertTrue(c.equals(ImmutableList.of("a", "b", "c")));
    assertFalse(c.equals(ImmutableList.of("a", "c", "b")));
    assertFalse(c.equals(ImmutableList.of("a", "b")));
    assertFalse(c.equals(ImmutableList.of("a", "b", "c", "d")));
  }

  public void testBuilderAdd() {
    ImmutableList<String> list =

    ImmutableList<Integer>[] array =
        (ImmutableList<Integer>[]) new ImmutableList<?>[] {ImmutableList.of(1)};
    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    ImmutableTypeToInstanceMap<Iterable<?>[]> map =
        ImmutableTypeToInstanceMap.<Iterable<?>[]>builder().put(type, array).build();
    assertEquals(1, map.size());

    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 ImmutableList<ManyValues> createAll() {
      ImmutableList.Builder<ManyValues> builder = ImmutableList.builder();
      double[] values = new double[5];
      for (double first : ImmutableList.of(1.1, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
        values[0] = first;
        values[1] = -44.44;
        for (double third : ImmutableList.of(33.33, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {

    Collection<String> c = ImmutableList.of();
    assertThat(ImmutableList.copyOf(c)).isSameInstanceAs(c);
  }

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

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

    }

    private static ImmutableList<ManyValues> createAll() {
      ImmutableList.Builder<ManyValues> builder = ImmutableList.builder();
      double[] values = new double[5];
      for (double first : ImmutableList.of(1.1, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
        values[0] = first;
        values[1] = -44.44;
        for (double third : ImmutableList.of(33.33, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {

        : result;
  }

  private static final class InverseEntries<K extends @Nullable Object, V extends @Nullable Object>
      extends ImmutableList<Entry<V, K>> {
    private final ImmutableList<Entry<K, V>> entries;

    InverseEntries(ImmutableList<Entry<K, V>> entries) {
      this.entries = entries;
    }

    @Override
    public Entry<V, K> get(int index) {