class ActionDispatch::Routing::Mapper

def devise_session(mapping, controllers) #:nodoc:
  resource :session, :only => [], :controller => controllers[:sessions], :path => "" do
    get   :new,     :path => mapping.path_names[:sign_in],  :as => "new"
    post  :create,  :path => mapping.path_names[:sign_in]
    match :destroy, :path => mapping.path_names[:sign_out], :as => "destroy", :via => mapping.sign_out_via
  end
end