Iterable<? extends T> a, Iterable<? extends T> b, Iterable<? extends T> c) {
    return concatNoDefensiveCopy(a, b, c);
  }

  /**
   * Returns a fluent iterable that combines four iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}, followed by

      Iterable<? extends T> a, Iterable<? extends T> b, Iterable<? extends T> c) {
    return concatNoDefensiveCopy(a, b, c);
  }

  /**
   * Returns a fluent iterable that combines four iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}, followed by