code: def render_heading(self, token):
          
          rendered = super().render_heading(token)
          content = self.parse_rendered_heading(rendered)
          if not (self.omit_title and token.level == 1
                  or token.level > self.depth
                  or any(cond(content) for cond in self.filter_conds)):
              self._headings.append((token.level, content))
          return rendered
docs: Overrides super().render_heading; stores rendered heading first,
          then returns it.