Person Class with relationship column and relationship

gistfile1.aw

use Doctrine\ORM\Mapping as ORM;  
use Symfony\Component\Validator\Constraints as Assert;

class Person {
     /**
       * @ORM\Column(type="string")
       * @Assert\NotBlank(message = "person_firstname_error")
       */
	protected $firstname = '';
	/**
	 * @ORM\Column(type="string")
	 *
	 * @Assert\NotBlank(message = "person_surname_error")
	 */
	protected $surname = '';
    /**
     * @ORM\OneToOne(targetEntity="UserAccount")
     * @ORM\JoinColumn(name="createdby", referencedColumnName="id")
     * @Assert\NotBlank(message = "person_createdby_error")
     */
    protected $creator; 
   /**
     * Set the user account creating the entity 
     * @param integer $createdby
     */
    public function setCreatedBy($createdby){
        $this->setCreator(loadEntity('UserAccount', $createdby)); 
    }
}