How to configure Yii2 i18n to translate from ru-RU (source language) to ru-RU (target language)?

Question

Yii

The situation is the following. The project is implemented in Russian, but in some cases messages in English may fly by. Previously, the default value was en-US, but at the moment internationalization is being implemented and there is a need to translate the application interface into English.
There is a configuration

return [
    ...,
    'language' => 'ru-RU',
    'sourceLanguage' => 'ru-RU',
    ...,
]

and

return [
    ...,
    'components' => [
        'i18n' => [
            'translations' => [
                'app*' => [
                    'class' => 'yii\i18n\PhpMessageSource',
                    'basePath' => '@frontend/messages',
                    'fileMap' => [
                        'app' => 'app.php',
                        'app/error' => 'error.php',
                    ],
                ],
            ],
        ],
    ],
    ...,
];

The problem is that if the source language and the target language are the same, then Yii2 does not translate, which is logical.
I found three solutions to this problem, but all of them are crutches:

1. Make a directory in @frontend/messages', for example, ru-RU2 and make the target language ru-RU2.
   
2. Make 'sourceLanguage' => null,
   
3. Make 'sourceLanguage' => 'ru',
   

Is there a better way to solve this problem through the configuration?
UPDATE.
Solution:
Add to configuration 'forceTranslation' => true,

return [
    ...,
    'components' => [
        'i18n' => [
            'translations' => [
                'app*' => [
                    'class' => 'yii\i18n\PhpMessageSource',
                    'basePath' => '@frontend/messages',
                    'fileMap' => [
                        'app' => 'app.php',
                        'app/error' => 'error.php',
                    ],
                    'forceTranslation' => true,
                ],
            ],
        ],
    ],
    ...,
];

Answer 1

www.yiiframework.com/doc-2.0/yii-i18n-phpmessageso...
forceTranslation - Whether to force message translation when the source and target languages ​​are the same.
Apparently this is what you need.