}
    Collections.shuffle(list, rand);
    if (forceSlow) {
      // Move zero index to front to force a matching character (if percent > 0)
      list.set(list.indexOf(0), list.get(0));
      list.set(0, 0);
    }
    // Get threshold in the range [0, length], rounding up to ensure that
    // non-zero percent values result in a non-zero threshold (so we always
    // have at least one matching character).

    }
    Collections.shuffle(list, rand);
    if (forceSlow) {
      // Move zero index to front to force a matching character (if percent > 0)
      list.set(list.indexOf(0), list.get(0));
      list.set(0, 0);
    }
    // Get threshold in the range [0, length], rounding up to ensure that
    // non-zero percent values result in a non-zero threshold (so we always
    // have at least one matching character).

 * <ol>
 *   <li>A pipeline starts at its leaf step (or steps), which is created from either a callable
 *       block or a {@link ListenableFuture}.
 *   <li>Each other step is derived from one or more input steps. At each step, zero or more objects
 *       can be captured for later closing.
 *   <li>There is one last step (the root of the tree), from which you can extract the final result