blocks to Markdown - that should stay as HTML
        if ($element->isDescendantOf(array('pre', 'code'))) {
            return;
        }

        // If the node has children, convert those to Markdown first
        if ($element->hasChildren()) {
            foreach ($element->getChildren() as $child) {
                $this->convertChildren($child);
            }
        }

        // Now that child nodes have been converted, convert the original node
        $markdown = $this->convertToMarkdown($element);

        // Create a DOM text node containing the Markdown equivalent of the original node

        // Replace the old $node e.g. '
Title
' with the new $markdown_node e.g. '### Title'
        $element->setFinalMarkdown($markdown);
    }

    /**
     * Convert to Markdown
     *
     * Converts an individual node into a #text node containing a string of its Markdown equivalent.
     *
     * Example: An 
 node with text content of 'Title' becomes a text node with content of '### Title'
     *
     * @param ElementInterface $element
     *
     * @return string The converted HTML as Markdown
     */
    protected function convertToMarkdown(ElementInterface $element)
    {
        $tag = $element->getTagName();

        // Strip nodes named in remove_nodes
        $tags_to_remove = explode(' ', $this->getConfig()->getOption('remove_nodes'));
        if (in_array($tag, $tags_to_remove)) {
            return false;
        }

        $converter = $this->environment->getConverterByTag($tag);

        return $converter->convert($element);
    }

    /**
     * @param string $markdown
     *
     * @return string
     */
    protected function sanitize($markdown)
    {
        $markdown = html_entity_decode($markdown, ENT_QUOTES, 'UTF-8');
        $markdown = preg_replace('/]+>/', '', $markdown); // Strip doctype declaration
        $markdown = trim($markdown); // Remove blank spaces at the beggining of the html

        /*
         * Removing unwanted tags. Tags should be added to the array in the order they are expected.
         * XML, html and body opening tags should be in that order. Same case with closing tags
         */
        $unwanted = array('', '', '', '', '', '', '', '
');

        foreach ($unwanted as $tag) {
            if (strpos($tag, '/') === false) {
                // Opening tags
                if (strpos($markdown, $tag) === 0) {
                    $markdown = substr($markdown, strlen($tag));
                }
            } else {
                // Closing tags
                if (strpos($markdown, $tag) === strlen($markdown) - strlen($tag)) {
                    $markdown = substr($markdown, 0, -strlen($tag));
                }
            }
        }

        $markdown = trim($markdown, "\n\r\0\x0B");

        return $markdown;
    }
}