code: def update(self, callback_method=values.unset, callback_url=values.unset,
                 friendly_name=values.unset):
          
          data = values.of({
              'CallbackMethod': callback_method,
              'CallbackUrl': callback_url,
              'FriendlyName': friendly_name,
          })
  
          payload = self._version.update(
              'POST',
              self._uri,
              data=data,
          )
  
          return TriggerInstance(
              self._version,
              payload,
              account_sid=self._solution['account_sid'],
              sid=self._solution['sid'],
          )
docs: Update the TriggerInstance
  
          :param unicode callback_method: The HTTP method to use to call callback_url
          :param unicode callback_url: The URL we call when the trigger fires
          :param unicode friendly_name: A string to describe the resource
  
          :returns: Updated TriggerInstance
          :rtype: twilio.rest.api.v2010.account.usage.trigger.TriggerInstance