This is an authentication user repository intended for use with mezzio-authentication. If you are using doctrine with your mezzio application, this will prevent you from writing redundant SQL queries or opening a new database connection. Instead, we directly fetch arrays with the entity manager.
You can install Authentication Doctrine User Repository using Composer:
$ composer require tigerman55/authentication-doctrine-user-repository
A complete example configuration can be found in example/full-config.php.