How to write Block_modName-Elem?

Please, help me get the class of element that changes its style depending on its block.

```
const block = cn('Block') // 'Block'
block({ modName: true }) // 'Block Block_modName'
block({ modName: true })('Elem') // Error. Type 'String' has no call signatures
```

Of course I can use `cn('Block_modName')('Elem')` but the meaning of the package is lost.