}
  }

  // Factory method that skips the null checks.  Used only when the elements
  // are guaranteed to be non-null.
  static <E> ImmutableList<E> unsafeDelegateList(List<? extends E> list) {
    switch (list.size()) {
      case 0:
        return of();
      case 1:
        return of(list.get(0));
      default:
        @SuppressWarnings("unchecked")