How to resolve undefined method `middleware' problem while runing rack-bug-Record and share programming errors

I have set up Rack-bug in ruby. I have added

 config.middleware.use ("Rack::Bug",
:secret_key => "epT5uCIchlsHCeR9dloOeAPG66PtHd9K8l0q9avitiaA/KUrY7DE52hD4yWY+8z1",
:password   => "some_pass"
)

into my config/environments/development.rb file. when i start server then load_environment': undefined methodmiddleware’ for # (NoMethodError) is showing. Howver in configuration same thing is mentioned in many sites. How can i resole this problem? I am using rail-2.2.2.

Originally posted 2013-08-31 07:15:15.