Example doesn't work

[kacejot]

Details:

[maxim@manjaro queue-sandbox]$ npm start

> app-server@0.1.0 start /home/maxim/Workspace/js/queue-sandbox
> node main.js

/home/maxim/Workspace/js/queue-sandbox/main.js:4
var q = new Queue();
        ^

TypeError: Queue is not a constructor
    at Object.<anonymous> (/home/maxim/Workspace/js/queue-sandbox/main.js:4:9)
    at Module._compile (internal/modules/cjs/loader.js:816:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:827:10)
    at Module.load (internal/modules/cjs/loader.js:685:32)
    at Function.Module._load (internal/modules/cjs/loader.js:620:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:877:12)
    at internal/main/run_main_module.js:21:11
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! app-server@0.1.0 start: `node main.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the app-server@0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/maxim/.npm/_logs/2019-08-30T12_38_08_650Z-debug.log