code: def serialize(self, now=None):
          
          created = self.created if self.created is not None else now
          el = etree.Element(utils.lxmlns("mets") + self.subsection, ID=self.id_string)
          if created:  # Don't add CREATED if none was parsed
              el.set("CREATED", created)
          status = self.get_status()
          if status:
              el.set("STATUS", status)
          if self.contents:
              el.append(self.contents.serialize())
          return el
docs: Serialize this SubSection and all children to lxml Element and return it.
  
          :param str now: Default value for CREATED if none set
          :return: dmdSec/techMD/rightsMD/sourceMD/digiprovMD Element with all children