tracker.Queues.clear(); TypeError: Cannot read property 'clear' of undefined

[charliex2]

运行 examples 里面的例子的时候，报如下错误

fibos-tracker/examples/index.js:71:16
tracker.Queues.clear();
               ^
TypeError: Cannot read property 'clear' of undefined
    at /Users/charlie/Code/demo/fibos-tracker/examples/index.js:71:16