/**
  * Assigne l'url du logo du marchand
  *
  * @param string $logo_url
  * @return boolean
  */
 public function setLogoUrl($logo_url)
 {
     if ($this->_locked) {
         return false;
     }
     $logo_url = trim($logo_url);
     if (!HIPAY_MAPI_UTILS::checkURL($logo_url) && $logo_url != '') {
         return false;
     }
     $this->logo_url = $logo_url;
     return true;
 }