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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_passage_plus(self, urn):
 """ Provisional route for GetPassagePlus request :param urn: URN to filter the resource :return: GetPassagePlus response """

        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/GetPassagePlus.xml",
            filters="urn={}".format(urn),
            request_urn=str(urn),
            full_urn=node.urn,
            prev_urn=node.prevId,
            next_urn=node.nextId,
            metadata={
                "groupname": [(literal.language, str(literal)) for literal in node.metadata.get(RDF_NAMESPACES.CTS.groupname)],
                "title": [(literal.language, str(literal)) for literal in node.metadata.get(RDF_NAMESPACES.CTS.title)],
                "description": [(literal.language, str(literal)) for literal in node.metadata.get(RDF_NAMESPACES.CTS.description)],
                "label": [(literal.language, str(literal)) for literal in node.metadata.get(RDF_NAMESPACES.CTS.label)]
            },
            citation=Markup(node.citation.export(Mimetypes.XML.CTS)),
            passage=Markup(node.export(Mimetypes.XML.TEI))
        )
        return r, 200, {"content-type": "application/xml"}