Create screenshot from region

**Short summary**
Trying to take screenshot on specific region of screen but still can't figure how


**Detailed question**
What expected
```
const {  Region ,ImageWriter,ScreenAction} = require("@nut-tree/nut-js");
ImageWriter.store(new ScreenAction.grabScreenRegion(new Region(x,y,w,h)),"myImage.png");

```
but get an error