'Update the ServiceInstance
:param unicode friendly_name: A human readable description of this resource
:param bool auto_create: Boolean flag specifying whether to auto-create threads.
:param unicode callback_url: URL Twilio will request for callbacks.
:returns: Updated ServiceInstance
:rtype: twilio.rest.preview.proxy.service.ServiceInstance'

def update(self, friendly_name=values.unset, auto_create=values.unset, callback_url=values.unset):

    return self._proxy.update(friendly_name=friendly_name, auto_create=auto_create, callback_url=callback_url)
