code: def _deserialize(self, value, attr, data):
          
          token_builder = URLSafeTimedSerializer(
              current_app.config['SECRET_KEY'],
              salt=data['verb'],
          )
          result = token_builder.loads(value, max_age=current_app.config[
              'OAISERVER_RESUMPTION_TOKEN_EXPIRE_TIME'])
          result['token'] = value
          result['kwargs'] = self.root.load(result['kwargs'], partial=True).data
          return result
docs: Serialize resumption token.