{
    "$jsonSchema": {
        "required": [
            "id",
            "locale"
        ],
        "properties": {
            "user": {
                "bsonType": [
                    "int",
                    "long"
                ],
                "description": "Telegram ID of user"
            },
            "locale": {
                "bsonType": [
                    "string",
                    "null"
                ],
                "description": "Preferred messages language according to user's preference"
            }
        }
    }
}