code: def _make_sections(self, **section_hdr_params):
          
          sect_story = []
          if not self.section_headings and len(self.sections):
              self.section_headings = self.sections.keys()
  
          for section_name in self.section_headings:
              section_story = self.sections[section_name]
              line = '-'*20
              section_head_text = '%s %s %s' % (line, section_name, line)
              title, title_sp = self._preformat_text(section_head_text,
                                                     **section_hdr_params)
              sect_story += [title, title_sp] + section_story
          return sect_story
docs: Flatten the sections into a single story list.