why import all module in bootstrap.js ?

```javascript
// import "../global/global.module";
// import "../main/main.module";
// import "../contacts/contacts.module";
// import "../mymessages/mymessages.module";
// import "../prefs/prefs.module";

// Google analytics
import '../util/ga';
```

just import '../util/ga' , the application can also work , and build smaller chunk