To get output of a historical Assessment
        :param assessment: string
        :param options: dict

def get_historical_output(self, assessment, options):
        """
        To get output of a historical Assessment
        :param assessment: string
        :param options: dict
        """
        responseFormat=None
        if options and 'format' in options and options['format'] is not None:
            responseFormat = options['format']
            options['format'] = None

        url = '/assessment/' + str(assessment) + '/output?' + urllib.parse.urlencode(options)
        response = self.http.downstream(url, responseFormat)
        return response