code: def _close_list(self):
          
          list_type = self.current_parent_element['attrs']['class']
          tag = LIST_TYPES[list_type]
  
          html = '</{t}>'.format(
              t=tag
          )
          self.cleaned_html += html
          self.current_parent_element['tag'] = ''
          self.current_parent_element['attrs'] = {}
docs: Add an close list tag corresponding to the currently open
          list found in current_parent_element.