public function assert(Zend_Acl $acl, Zend_Acl_Role_Interface $role = null, Zend_Acl_Resource_Interface $resource = null, $privilege = null)
 {
     if (ProfileTable::PUBLIC_FLAG_FRIEND == $resource->getPublicFlag()) {
         return 'self' === $role->getRoleId() || 'friend' === $role->getRoleId();
     }
     if (ProfileTable::PUBLIC_FLAG_PRIVATE == $resource->getPublicFlag()) {
         return 'self' === $role->getRoleId();
     }
     return true;
 }