# File lib/devise/test_helpers.rb, line 60
    def sign_out(resource_or_scope)
      scope = Devise::Mapping.find_scope!(resource_or_scope)
      @controller.instance_variable_set("@current_#{scope}""@current_#{scope}", nil)
      user = warden.instance_variable_get(:@users).delete(scope)
      warden.session_serializer.delete(scope, user)
    end