docs: def _make_links_absolute(html, base_url):
      """
      Make all links absolute.
      """
      url_changes = []
  
      soup = BeautifulSoup(html)
      for tag in soup.find_all('a', href=True):
          old = tag['href']
          fixed = urljoin(base_url, old)
          if old != fixed:
              url_changes.append((old, fixed))
              tag['href'] = fixed
  
      for tag in soup.find_all('img', src=True):
          old = tag['src']
          fixed = urljoin(base_url, old)
          if old != fixed:
              url_changes.append((old, fixed))
              tag['src'] = fixed
  
      return mark_safe(six.text_type(soup)), url_changes