public function actionStat($user = null)
    {
        if ($user === null) {
            $count = User::find()->count();
            echo "Total number of user(s): " . $count . "\n";
            if ($count == 0) {
                return static::EXIT_CODE_NORMAL;
            }
            $last = User::find()->orderByCreatedAt(SORT_DESC)->one();
            /* @var $last User */
            echo "Latest user (" . $last->getID() . ") registered at " . $last->getCreatedAt() . "\n";
            return static::EXIT_CODE_NORMAL;
        }
        $user = $this->getUser($user);
        return static::EXIT_CODE_NORMAL;
    }