README.md in the_garage-2.3.3 vs README.md in the_garage-2.4.0

@@ -45,13 +45,19 @@
     perms.permits! :read
   end
 end
 ```
 
-In your controller class:
+In your controller classes:
 
 ```ruby
+class ApplicationController < ActionController::Base
+  include Garage::ControllerHelper
+  
+  # ...
+end
+
 class EmployeesController < ApplicationController
   include Garage::RestfulActions
 
   def require_resources
     @resources = Employee.all
@@ -177,9 +183,24 @@
   # Whether verify permission and access in `RestfulActions`.
   def verify_permission?
     true
   end
 end
+```
+
+## Distributed tracing
+In case you use auth-server strategy, you can setup distributed tracing for the service communication between garage application and auth server.
+Currently, we support following tracers:
+
+- `aws-xray` using [aws-xray](https://github.com/taiki45/aws-xray) gem.
+  - Bundle `aws-xray` gem in your application.
+  - Configure `service` option for a logical service name of the auth server.
+
+```ruby
+# e.g. aws-xray tracer
+require 'aws/xray'
+Garage::Tracer::AwsXrayTracer.service = 'your-auth-server-name'
+Garage.configuration.tracer = Garage::Tracer::AwsXrayTracer
 ```
 
 ## Development
 
 See [DEVELOPMENT.md](DEVELOPMENT.md).