docs: def show_revisions(context, page, content_type, lang=None):
      """Render the last 10 revisions of a page content with a list using
          the ``pages/revisions.html`` template"""
      if not pages_settings.PAGE_CONTENT_REVISION:
          return {'revisions': None}
      revisions = Content.objects.filter(page=page, language=lang,
                                  type=content_type).order_by('-creation_date')
      if len(revisions) < 2:
          return {'revisions': None}
      return {'revisions': revisions[0:10]}