code: def get_cache_key(request, page, lang, site_id, title):
      
      from cms.cache import _get_cache_key
      from cms.templatetags.cms_tags import _get_page_by_untyped_arg
  
      from cms.models import Page
      if not isinstance(page, Page):
          page = _get_page_by_untyped_arg(page, request, site_id)
      if not site_id:
          try:
              site_id = page.node.site_id
          except AttributeError:  # CMS_3_4
              site_id = page.site_id
      if not title:
          return _get_cache_key('page_tags', page, '', site_id) + '_type:tags_list'
      else:
          return _get_cache_key('title_tags', page, lang, site_id) + '_type:tags_list'
docs: Create the cache key for the current page and tag type