casl react redux

1import { AbilityBuilder } from 'casl'
2
3function subjectName(item) { 
4if (!item || typeof item === 'string') {
5    return item  
6    }  
7return item.__type
8}
9export default AbilityBuilder.define({ subjectName }, can => {
10    can(['read', 'create'], 'Todo') 
11    can(['update', 'delete'], 'Todo', { assignee: 'me' })
12});