call

# File actionpack/lib/action_dispatch/middleware/request_id.rb, line 24
    def call(env)
      req = ActionDispatch::Request.new env
      req.request_id = make_request_id(req.x_request_id)
      @app.call(env).tap { |_status, headers, _body| headers[X_REQUEST_ID] = req.request_id }
    end