public static function findByKeyfield($keyfield, $status = self::STATUS_ACTIVE)
    {
        if ($status === null) {
            return static::find()->where(['or', ['email' => $keyfield], ['username' => $keyfield]])->limit(1)->one();
        }
        return static::find()->where(['and', ['status' => $status], ['or', ['email' => $keyfield], ['username' => $keyfield]]])->limit(1)->one();
    }