code: def resource_etree_element(self, resource, element_name='url'):
          
          e = Element(element_name)
          sub = Element('loc')
          sub.text = resource.uri
          e.append(sub)
          if (resource.timestamp is not None):
              # Create appriate element for timestamp
              sub = Element('lastmod')
              sub.text = str(resource.lastmod)  # W3C Datetime in UTC
              e.append(sub)
          md_atts = {}
          for att in ('capability', 'change', 'hash', 'length', 'path', 'mime_type',
                      'md_at', 'md_completed', 'md_from', 'md_until'):
              val = getattr(resource, att, None)
              if (val is not None):
                  md_atts[self._xml_att_name(att)] = str(val)
          if (len(md_atts) > 0):
              md = Element('rs:md', md_atts)
              e.append(md)
          # add any <rs:ln>
          if (hasattr(resource, 'ln') and
                  resource.ln is not None):
              for ln in resource.ln:
                  self.add_element_with_atts_to_etree(e, 'rs:ln', ln)
          if (self.pretty_xml):
              e.tail = "\n"
          return(e)
docs: Return xml.etree.ElementTree.Element representing the resource.
  
          Returns and element for the specified resource, of the form <url>
          with enclosed properties that are based on the sitemap with extensions
          for ResourceSync.