ruby - Why is verification deprecated in Rails 3? -

my rails log telling me verify deprecated in rails 3 , available plugin. great, why? there must reason this, main question new convention handling following in rails 3?

verify :params => [:username, :password],     :render => {:action => "new"},     :add_flash => {     :error => "username , password required log in" } 

the rails 3 guide still says use verify did in rails 2. out of date suppose!

rails 3 has taken moving lot of "non-core" functionality plugins give people chance opt-out default. acts_as_tree , acts_as_list examples of things removed while ago, available standard gem plugins.

if want use it, add gemfile.