How to use multiple database connections in Silex?

Question

PHP

It is necessary in a project with silex + doctrine2 to separate connections to the database for writing and reading. on the Internet there are ways to configure the type:

$app->register(new Silex\Provider\DoctrineServiceProvider(), array(
    'dbs.options' => array (
        'mysql_read' => array(
            'driver'    => 'pdo_mysql',
            'host'      => 'mysql_read.someplace.tld',
            'dbname'    => 'my_database',
            'user'      => 'my_username',
            'password'  => 'my_password',
            'charset'   => 'utf8mb4',
        ),
        'mysql_write' => array(
            'driver'    => 'pdo_mysql',
            'host'      => 'mysql_write.someplace.tld',
            'dbname'    => 'my_database',
            'user'      => 'my_username',
            'password'  => 'my_password',
            'charset'   => 'utf8mb4',
        ),
    ),
  ));

but how to work with using ORM is not clear.