def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
def detail_export(self, request, pk=None):
        serializer = ConditionExportSerializer(self.get_object())
        xml = ConditionRenderer().render([serializer.data])
        return XMLResponse(xml, name=self.get_object().key)