code: def _get_passage(self, urn):
          
          urn = URN(urn)
          subreference = None
          if len(urn) < 4:
              raise InvalidURN
          if urn.reference is not None:
              subreference = str(urn.reference)
          node = self.resolver.getTextualNode(textId=urn.upTo(URN.NO_PASSAGE), subreference=subreference)
  
          r = render_template(
              "cts/GetPassage.xml",
              filters="urn={}".format(urn),
              request_urn=str(urn),
              full_urn=node.urn,
              passage=Markup(node.export(Mimetypes.XML.TEI))
          )
          return r, 200, {"content-type": "application/xml"}
docs: Provisional route for GetPassage request
  
          :param urn: URN to filter the resource
          :return: GetPassage response