public function ban(User $user)
    {
        $user->is_blocked = ! $user->is_blocked;
        $user->save();

        if ($user->is_blocked) {
            return $this->notifySuccess('User ' . $user->name . ' blocked!');
        } else {
            return $this->notifySuccess('User ' . $user->name . ' un-blocked!');
        }
    }