src/api/postIdSet.js
/**
     * Add a post id to the set.
     * @return true if the id was already in the set, false if not.
     */
Add a post id to the set.
@return true if the id was already in the set, false if not.
Add a post id to the set . @return true if the id was already in the set false if not .
add(id) {
        const contains = this.ids.has(id);
        this.ids.add(id);
        return contains;
    }
add ( id ) { const contains = this . ids . has ( id ) ; this . ids . add ( id ) ; return contains ; }
Add a post id to the set.
Add a post id to the set .