docs: def get_node(self):
          """return etree Element representing this slide"""
          # already added title, text frames
          # add animation chunks
          if self.animations:
              anim_par = el("anim:par", attrib={"presentation:node-type": "timing-root"})
              self._page.append(anim_par)
              anim_seq = sub_el(
                  anim_par, "anim:seq", attrib={"presentation:node-type": "main-sequence"}
              )
              for a in self.animations:
                  a_node = a.get_node()
                  anim_seq.append(a_node)
  
          # add notes now (so they are last)
          if self.notes_frame:
              notes = self.notes_frame.get_node()
              self._page.append(notes)
          if self.footer:
              self._page.attrib[ns("presentation", "use-footer-name")] = self.footer.name
          return self._page