call delete item but send the callback to the api

send-callback-to-api.ts

private removeItem(item: Item) {
       
       let index = this.items.indexOf(item);
       //remove the item
       this.items.splice(index, 1);
       
       //call back-end server to remove the item from the DB
        this.itemService.deleteItem(item.id,()=>this.items.splice(index, 0, item)).subscribe(
            //do some stuff);
    }