code: def make_heading_affiliations(self, heading_div):
          
          #Get all of the aff element tuples from the metadata
          affs = self.article.root.xpath('./front/article-meta/aff')
          #Create a list of all those pertaining to the authors
          author_affs = [i for i in affs if 'aff' in i.attrib['id']]
          #Count them, used for formatting
          if len(author_affs) == 0:
              return None
          else:
              affs_list = etree.SubElement(heading_div,
                                           'ul',
                                           {'id': 'affiliations',
                                            'class': 'simple'})
  
          for aff in author_affs:
              #Create a span element to accept extracted content
              aff_item = etree.SubElement(affs_list, 'li')
              aff_item.attrib['id'] = aff.attrib['id']
              #Get the first label node and the first addr-line node
              label = aff.find('label')
              addr_line = aff.find('addr-line')
              if label is not None:
                  bold = etree.SubElement(aff_item, 'b')
                  bold.text = all_text(label) + ' '
              if addr_line is not None:
                  append_new_text(aff_item, all_text(addr_line))
              else:
                  append_new_text(aff_item, all_text(aff))
docs: Makes the content for the Author Affiliations, displays after the
          Authors segment in the Heading.
  
          Metadata element, content derived from FrontMatter