* single-threaded.
   */
  @GwtIncompatible // GWT is single threaded
  public void testCopyOf_threadSafe() {
    /*
     * The actual collections that we pass as inputs will be wrappers around these, so
     * ImmutableSet.copyOf won't short-circuit because it won't see an ImmutableSet input.
     */
    ImmutableList<ImmutableSet<String>> distinctCandidatesByAscendingSize =

   * single-threaded.
   */
  @GwtIncompatible // GWT is single threaded
  public void testCopyOf_threadSafe() {
    /*
     * The actual collections that we pass as inputs will be wrappers around these, so
     * ImmutableSet.copyOf won't short-circuit because it won't see an ImmutableSet input.
     */
    ImmutableList<ImmutableSet<String>> distinctCandidatesByAscendingSize =