When does a database connection close in Doctrine?

Question

Doctrine ORM

Installed Doctrine2 as an ORM in a pure php project. I create an entity manager at the entry point $em = EntityManager::create($conn, $config);, if I understand correctly, then at this moment a connection to the database is created. It turns out that if I do not manually call $em->getConnection()->close();, then the connection will not be closed, right?