    # File lib/rack/session/cookie.rb, line 105
          def initialize(app, options={})
            @secrets = options.values_at(:secret, :old_secret).compact
            warn "SECURITY WARNING: No secret option provided to Rack::Session::Cookie.\nThis poses a security threat. It is strongly recommended that you\nprovide a secret to prevent exploits that may be possible from crafted\ncookies. This will not be supported in future versions of Rack, and\nfuture versions will even invalidate your existing user cookies.\n\nCalled from: \#{caller[0]}.\n" unless @secrets.size >= 1
            @coder  = options[:coder] ||= Base64::Marshal.new
            super(app, options.merge!(:cookie_only => true))
          end