code: def update(self, webhook_method=values.unset, webhook_filters=values.unset,
                 pre_webhook_url=values.unset, post_webhook_url=values.unset,
                 pre_webhook_retry_count=values.unset,
                 post_webhook_retry_count=values.unset, target=values.unset):
          
          data = values.of({
              'WebhookMethod': webhook_method,
              'WebhookFilters': serialize.map(webhook_filters, lambda e: e),
              'PreWebhookUrl': pre_webhook_url,
              'PostWebhookUrl': post_webhook_url,
              'PreWebhookRetryCount': pre_webhook_retry_count,
              'PostWebhookRetryCount': post_webhook_retry_count,
              'Target': target,
          })
  
          payload = self._version.update(
              'POST',
              self._uri,
              data=data,
          )
  
          return WebhookInstance(self._version, payload, )
docs: Update the WebhookInstance
  
          :param unicode webhook_method: The HTTP method to be used when sending a webhook request.
          :param unicode webhook_filters: The list of webhook event triggers that are enabled for this Service.
          :param unicode pre_webhook_url: The absolute url the pre-event webhook request should be sent to.
          :param unicode post_webhook_url: The absolute url the post-event webhook request should be sent to.
          :param unicode pre_webhook_retry_count: The number of retries in case of pre-event webhook request failures.
          :param unicode post_webhook_retry_count: The number of retries in case of post-event webhook request failures.
          :param WebhookInstance.Target target: The routing target of the webhook.
  
          :returns: Updated WebhookInstance
          :rtype: twilio.rest.messaging.v1.webhook.WebhookInstance