uuid()
Instance Public methods
Returns the unique request id, which is based off either the X-Request-Id
header that can be generated by a firewall, load balancer, or web server or
by the RequestId middleware (which sets the
action_dispatch.request_id environment variable).
This unique ID is useful for tracing a request from end-to-end as part of
logging or debugging. This relies on the rack variable set by the ActionDispatch::RequestId middleware.