Deque<NodeAndRemainingSuccessors<N>> stack = new ArrayDeque<>();
    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;

    Deque<NodeAndRemainingSuccessors<N>> stack = new ArrayDeque<>();
    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;

                stack.push(list);
            }

            list.add(parseItem(isCombination, isDigit, version.substring(startIndex)));
        }

        while (!stack.isEmpty()) {
            list = (ListItem) stack.pop();
            list.normalize();
        }
    }

    private static Item parseItem(boolean isDigit, String buf) {

    }
  }

  /**
   * Returns a string containing the result of {@link Throwable#toString() toString()}, followed by
   * the full, recursive stack trace of {@code throwable}. Note that you probably should not be
   * parsing the resulting string; if you need programmatic access to the stack frames, you can call
   * {@link Throwable#getStackTrace()}.
   */
  @GwtIncompatible // java.io.PrintWriter, java.io.StringWriter

     * @param error the error that caused this log
     */
    void debug(CharSequence content, Throwable error);

    /**
     * Sends an exception to the user in the <b>debug</b> error level.
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error the error that caused this log
     */
    void debug(Throwable error);

    void debug(Supplier<String> content);

    public void test_stackTrace() {
        // Test that stack trace is properly captured
        LdapOperationException exception = new LdapOperationException("Stack trace test");
        StackTraceElement[] stackTrace = exception.getStackTrace();

        assertNotNull(stackTrace);
        assertTrue(stackTrace.length > 0);
        // Verify that current test method appears in stack trace
        boolean foundTestMethod = false;

    }

    public void test_stackTrace() {
        // Test that stack trace is properly captured
        ThemeException exception = new ThemeException("Stack trace test");

        assertNotNull(exception.getStackTrace());
        assertTrue(exception.getStackTrace().length > 0);

        // Verify that this test method appears in the stack trace
        boolean foundTestMethod = false;

     * setException(stackOverflowError) would fail:
     *
     * - If the stack overflowed before set()/setValue() could even store the result in the output
     * Future, then a call setException() would likely also overflow.
     *
     * - If the stack overflowed after set()/setValue() stored its result, then a call to
     * setException() will be a no-op because the Future is already done.

        assertTrue("Should contain Thread: entries", hasThreadEntry);

        // Verify format - should contain stack trace entries
        boolean hasStackTrace = capturedOutput.stream().anyMatch(line -> line.startsWith("\tat "));
        assertTrue("Should contain stack trace entries", hasStackTrace);
    }

    public void test_processThreadDump_withNullConsumer() {
        try {

        // Create a ServletException with a specific message
        String errorMessage = "Stack trace test error";
        ServletException servletException = new ServletException(errorMessage);

        // Wrap it in ServletRuntimeException
        ServletRuntimeException runtimeException = new ServletRuntimeException(servletException);

        // Verify stack trace is available
        StackTraceElement[] stackTrace = runtimeException.getStackTrace();