def set_session(env, sid, session_data, options) # rack 1.x compatibilty
      write_session(Rack::Request.new(env), sid, session_data, options)
    end
def set_session(env, sid, session_data, options) # rack 1.x compatibilty
      write_session(Rack::Request.new(env), sid, session_data, options)
    end
Rack 1.* method