Nestjs -Middleware unit testing

I am working on a Nestjs application, and i would like to make a unit test for the following middleware:

@Injectable()
export class LocaleMiddleware implements NestMiddleware {
    use(req: Request, res: Response, next: () => void) {
        if (!req.headers['accept-language'] || !(req.headers['accept-language']! in LocaleEnum)) {
            req.headers['accept-language'] = LocaleEnum.en;
        }
        next();
    }
}

How can mock the request and check that accept-language is assigned correctly ??