How to cast object in object into Angular Class (Type)

Possible answer

export interface Category {
 name: string;
 prop: string;
}
export class Post {
    category: Category[];
    constructor(obj: any) {
        this.category = obj.category as Category[];
    }
}
`

The keyword as allowed me to properly cast my object to desired class and fixed the error ´TS2322: Type '{}' is not assignable to type ...´. Thanks!