code: def invalidate(self):
          
  
          cache.delete(self.PAGE_LANGUAGES_KEY % (self.id))
          cache.delete('PAGE_FIRST_ROOT_ID')
          self._languages = None
          self._complete_slug = None
          self._content_dict = dict()
  
          p_names = [p.name for p in get_placeholders(self.get_template())]
          if 'slug' not in p_names:
              p_names.append('slug')
          if 'title' not in p_names:
              p_names.append('title')
          # delete content cache, frozen or not
          for name in p_names:
              # frozen
              cache.delete(PAGE_CONTENT_DICT_KEY % (self.id, name, 1))
              # not frozen
              cache.delete(PAGE_CONTENT_DICT_KEY % (self.id, name, 0))
  
          cache.delete(self.PAGE_URL_KEY % (self.id))
docs: Invalidate cached data for this page.