title: How can I "composer require" just Doctrine ORM EntityManagerInterface
body: <p>My recently created package rely on repository interfaces. One of the choices for a source data is database and Doctrine ORM. As database is just one of possible choices, I do not want to integrate the whole Doctrine ORM package, but to create an appropriate adapter that just depends on Doctrine\ORM\EntityManagerInterface. The question is how can I "composer require" partially from Doctrine ORM ? I'd like to add, that I could not have found any separate package with the Doctrine ORM EntityManagerInterface.</p>
  
  <p>Thanks in advance.</p>