code: def oaiset_url(self):
          
          return url_for(
              'invenio_oaiserver.response',
              verb='ListRecords',
              metadataPrefix='oai_dc', set=self.oaiset_spec, _external=True)
docs: Return the OAISet URL for given community.
  
          :returns: URL of corresponding OAISet.
          :rtype: str