# File lib/omniauth/strategies/shibboleth.rb, line 62
      def callback_phase
        if options.debug
          # dump attributes
          return [
            200,
            {
              'Content-Type' => 'text/plain'
            },
            ["!!!!! This message is generated by omniauth-shibboleth. To remove it set :debug to false. !!!!!\n#{request_params.sort.map {|i| "#{i[0]}: #{i[1]}" }.join("\n")}"]
          ]
        end
        return fail!(:no_shibboleth_session) unless (request_param(options.shib_session_id_field.to_s) || request_param(options.shib_application_id_field.to_s))
        return fail!(:empty_uid) if options.fail_with_empty_uid && option_handler(options.uid_field).empty?
        super
      end