Entity/Menu.php
public function setSite(\Application\Sonata\PageBundle\Entity\Site $site = null)
    {
        $this->site = $site;

        return $this;
    }
public function setSite(\Application\Sonata\PageBundle\Entity\Site $site = null)
    {
        $this->site = $site;

        return $this;
    }
Set site

@param \Application\Sonata\PageBundle\Entity\Site $site
@return Menu