var $icon = $searchButton.find("i.fa-search");
    if ($icon.length > 0) {
      $icon.removeClass("fa fa-search").addClass("spinner-border spinner-border-sm");
    }
    setTimeout(function() {
      $searchButton.prop("disabled", false);
      var $spinner = $searchButton.find(".spinner-border");
      if ($spinner.length > 0) {
        $spinner.removeClass("spinner-border spinner-border-sm").addClass("fa fa-search");
      }

    }

    /**
     * Show progress indicator
     */
    function showProgressIndicator() {
        // Reset all steps
        $('.progress-step').removeClass('active completed');
        elements.progressMessage.text('');
        elements.progressIndicator.removeClass('d-none');
    }

    /**
     * Hide progress indicator
     */
    function hideProgressIndicator() {

    var $icon = $searchButton.find("i.fa-search");
    if ($icon.length > 0) {
      $icon.removeClass("fa fa-search").addClass("spinner-border spinner-border-sm");
    }
    setTimeout(function() {
      $searchButton.prop("disabled", false);
      var $spinner = $searchButton.find(".spinner-border");
      if ($spinner.length > 0) {
        $spinner.removeClass("spinner-border spinner-border-sm").addClass("fa fa-search");
      }

    stack.addLast(new NodeAndRemainingSuccessors<>(startNode));

    while (!stack.isEmpty()) {
      // To peek at the top two items, we need to temporarily remove one.
      NodeAndRemainingSuccessors<N> top = stack.removeLast();
      NodeAndRemainingSuccessors<N> prev = stack.peekLast();
      stack.addLast(top);

      N node = top.node;
      N previousNode = prev == null ? null : prev.node;

 * defined as the <i>least</i> element in the queue according to the queue's comparator. But unlike
 * a regular priority queue, the methods {@link #peekLast}, {@link #pollLast} and {@link
 * #removeLast} are also provided, to act on the <i>greatest</i> element in the queue instead.
 *
 * <p>A min-max priority queue can be configured with a maximum size. If so, each time the size of

 * defined as the <i>least</i> element in the queue according to the queue's comparator. But unlike
 * a regular priority queue, the methods {@link #peekLast}, {@link #pollLast} and {@link
 * #removeLast} are also provided, to act on the <i>greatest</i> element in the queue instead.
 *
 * <p>A min-max priority queue can be configured with a maximum size. If so, each time the size of

    Deque<Spliterator<T>> splits = new ArrayDeque<>();
    splits.addLast(stream.spliterator());

    while (!splits.isEmpty()) {
      Spliterator<T> spliterator = splits.removeLast();

      if (spliterator.getExactSizeIfKnown() == 0) {
        continue; // drop this split
      }

      // Many spliterators will have trySplits that are SUBSIZED even if they are not themselves

    Deque<Spliterator<T>> splits = new ArrayDeque<>();
    splits.addLast(stream.spliterator());

    while (!splits.isEmpty()) {
      Spliterator<T> spliterator = splits.removeLast();

      if (spliterator.getExactSizeIfKnown() == 0) {
        continue; // drop this split
      }

      // Many spliterators will have trySplits that are SUBSIZED even if they are not themselves