code: def fetch(self):
          
          params = values.of({})
  
          payload = self._version.fetch(
              'GET',
              self._uri,
              params=params,
          )
  
          return CallSummaryInstance(self._version, payload, call_sid=self._solution['call_sid'], )
docs: Fetch a CallSummaryInstance
  
          :returns: Fetched CallSummaryInstance
          :rtype: twilio.rest.insights.v1.summary.CallSummaryInstance