Using Isolate in react-jss

I'm trying to use isolate with react-jss, but there's no docs. I'm currently trying like this:

```
const useStyles = createUseStyles({
mark: props => ({
isolate: true,
color: [ [ props.headingColor ], '!important' ],
fontFamily: [ [ props.fontFamily ], '!important' ],
'& mark': {
color: props.highlightColor,
background: props.highlightBackground
}
})
});
```

Any ideas?