call

# File actionpack/lib/action_dispatch/middleware/cookies.rb, line 485
    def call(env)
      status, headers, body = @app.call(env)

      if cookie_jar = env['action_dispatch.cookies']
        cookie_jar.write(headers)
        if headers[HTTP_HEADER].respond_to?(:join)
          headers[HTTP_HEADER] = headers[HTTP_HEADER].join("\n")
        end
      end

      [status, headers, body]
    end