title: Symfony3 - Extend namespace
body: <p>I have the following directory structure in my symfony3 structure:</p>
  
  <pre><code>src
      AppBundle
          AppBundle.php
          Entity
              User
                  User.php
                  UserRepository.php
  </code></pre>
  
  <p>On top of my User.php:</p>
  
  <pre><code>&lt;?php
  
  namespace AppBundle\Entity\User;
  
  use Doctrine\ORM\Mapping as ORM;
  use Symfony\Component\Security\Core\User\UserInterface;
  
  /**
   * @ORM\Table(name="user")
   * @ORM\Entity(repositoryClass="AppBundle\Entity\User\UserRepository")
   */
  class User implements UserInterface {
  </code></pre>
  
  <p>and it tells me:</p>
  
  <pre><code>undefined constant User
  </code></pre>
  
  <p>Is there any way extending the namespace?</p>
  
  <p>Thanks and Greetings!</p>
  
  <p>EDIT:</p>
  
  <p>occurrence of "user":</p>
  
  <pre><code>security:
      providers:
          in_memory:
              memory:
                  users:
                      admin:
                          password: admin
                          roles: 'ROLE_ADMIN'
          our_db_provider:
              entity:
                  class: AppBundle:User
                  property: username
  
      encoders:
          AppBundle\Entity\User\User:
              algorithm: bcrypt
  </code></pre>