docs: def add_list(self, bl):
          """
          note that this pushes the cur_element, but doesn't pop it.
          You'll need to do that
          """
          # text:list doesn't like being a child of text:p
          if self.cur_element is None:
              self.add_text_frame()
          self.push_element()
          self.cur_element._text_box.append(bl.node)
          style = bl.style_name
          if style not in self._preso._styles_added:
              self._preso._styles_added[style] = 1
              content = bl.default_styles_root()[0]
              self._preso._auto_styles.append(content)
          self.cur_element = bl