public static function saveMessage($message, $category = 'database')
    {
        $languageSources = \lajax\translatemanager\models\LanguageSource::find()->where(['category' => $category])->all();

        $messages = [];
        foreach ($languageSources as $languageSource) {
            $messages[$languageSource->message] = $languageSource->id;
        }

        if (empty($messages[$message])) {
            $languageSource = new \lajax\translatemanager\models\LanguageSource();
            $languageSource->category = $category;
            $languageSource->message = $message;
            $languageSource->save();
        }
    }