def update(self, webhook_url=values.unset, friendly_name=values.unset,<EOL>reachability_webhooks_enabled=values.unset,<EOL>acl_enabled=values.unset):
return self._proxy.update(<EOL>webhook_url=webhook_url,<EOL>friendly_name=friendly_name,<EOL>reachability_webhooks_enabled=reachability_webhooks_enabled,<EOL>acl_enabled=acl_enabled,<EOL>)<EOL>
Update the ServiceInstance

:param unicode webhook_url: A URL that will receive event updates when objects are manipulated.
:param unicode friendly_name: Human-readable name for this service instance
:param bool reachability_webhooks_enabled: True or false - controls whether this instance fires webhooks when client endpoints connect to Sync
:param bool acl_enabled: true or false - determines whether token identities must be granted access to Sync objects via the Permissions API in this Service.

:returns: Updated ServiceInstance
:rtype: twilio.rest.sync.v1.service.ServiceInstance