def after_failed_fetch(options = {}, method = :push, &block)
      raise BlockNotGiven unless block_given?
      _after_failed_fetch.send(method, [block, options])
    end
def after_failed_fetch(options = {}, method = :push, &block)
      raise BlockNotGiven unless block_given?
      _after_failed_fetch.send(method, [block, options])
    end
A callback that runs if no user could be fetched, meaning there is now no user logged in.

 Parameters:
 <options> Some options which specify when the callback should be executed
   scope  - Executes the callback only if it matches the scope(s) given
 <block> A block to contain logic for the callback
   Block Parameters: |user, auth, scope|
     user - The authenticated user for the current scope
     auth - The warden proxy object
     opts - any options passed into the authenticate call including :scope

 Example:
   Warden::Manager.after_failed_fetch do |user, auth, opts|
     I18n.locale = :en
   end

 :api: public