if (elementStack.contains(element)) {
                while (!elementStack.getFirst().equals(element)) {
                    visitor.onEndHtmlElement(elementStack.removeFirst());
                }
                elementStack.removeFirst();
                visitor.onEndHtmlElement(element);
            }
        }

        private void unwindTo(Collection<String> ancestors, TokenVisitor visitor) {

        scanner.skip(WHITESPACE_WITH_EOL);
        scanner.mark();
        scanner.find(END_ELEMENT_NAME);
        String elementName = scanner.region().toLowerCase();
        if (isEnd) {
            visitor.onEndHtmlElement(elementName);
        } else {
            visitor.onStartHtmlElement(elementName);
        }

        // attributes
        scanner.skip(WHITESPACE_WITH_EOL);

        }

        void onHtmlElementAttribute(String name, String value) {
        }

        void onStartHtmlElementComplete(String name) {
        }

        void onEndHtmlElement(String name) {
        }

        void onStartJavadocTag(String name) {
        }

        void onEndJavadocTag(String name) {
        }

        void onText(String text) {
        }

                    tagStack.addFirst(name);
                    return;
                }
            }
            throw new UnsupportedOperationException();
        }

        @Override
        void onEndHtmlElement(String name) {
            if (!tagStack.isEmpty() && tagStack.getFirst().equals(name)) {
                tagStack.removeFirst();
                handlerStack.removeFirst().onEndElement(name);
            }