Collections.addAll(all, e1, e2, e3, e4, e5, e6);
    Collections.addAll(all, others);
    return copyOf(all.iterator());
  }

  /** ImmutableSet.of API that is friendly to use from JavaScript. */
  @JsMethod(name = "of")
  static <E> ImmutableSet<E> jsOf(E... elements) {
    return copyOf(elements);
  }

  @JsMethod
  public static <E> ImmutableSet<E> copyOf(E[] elements) {

   * This needs to be a @JsMethod so that J2CL knows to look for a JavaScript implemention of
   * it in Platform.native.js. (The JavaScript implementation inline below is visible to *GWT*, but
   * *J2CL* doesn't look at it.)
   *
   * However, once it's a @JsMethod, GWT produces a warning. That's because (a) the *other* purpose
   * of @JsMethod is to make a method *callable* from JavaScript and (b) this method would not be