Unexpected T_STRING, expecting '{'

Bonjour,
Une erreur apparai dans mon script et impossible de trouver ou :

Parse error: syntax error, unexpected T_STRING, expecting '{' in /homez.429/danslaru/www/modules/mod_roknavmenu/lib/librokmenu/RokMenuNodeBase.php on line 16

voila mon code quelqu'un aurai t'il la solution ? :
<?php
/**
* @version 2.1 October 7, 2010
* @author RocketTheme http://www.rockettheme.com
* @copyright Copyright (C) 2007 - 2010 RocketTheme, LLC
* @license http://www.gnu.org/licenses/gpl-2.0.html GNU/GPLv2 only
*/

require_once(dirname(__FILE__) . '/RokMenuIterator.php');

if (!class_exists('RokMenuNodeBase')) {

/**
*
*/
class RokMenuNodeBase implements IteratorAggregate {

function getIterator() {
return new RokMenuIterator($this);
}

/**
* @var int
*/
protected $id = 0;

/**
* @var int
*/
protected $parent = 0;

/**
* @var RokMenuNodeBase
*/
protected $parentRef = null;

/**
* @var int
*/
protected $level = -1;

/**
* @var array
*/
protected $children = array();


/**
* Gets the id
* @access public
* @return integer
*/
public function getId() {
return $this->id;
}

/**
* Sets the id
* @access public
* @param integer $id
*/
public function setId($id) {
$this->id = $id;
}

/**
* Gets the level
* @access public
* @return integer
*/
public function getLevel() {
return $this->level;
}

/**
* Sets the level
* @access public
* @param integer $level
*/
public function setLevel($level) {
$this->level = $level;
}


/**
* Gets the parent
* @access public
* @return integer
*/
public function getParent() {
return $this->parent;
}

/**
* Sets the parent
* @access public
* @param integer $parent
*/
public function setParent($parent) {
$this->parent = $parent;
}

/**
* @return RokMenuNodeBase
*/
public function getParentRef() {
return $this->parentRef;
}

/**
* @param RokmenuNodeBase $parentRef
* @return void
*/
public function setParentRef(RokmenuNodeBase & $parentRef) {
$this->parentRef = &$parentRef;
}

/**
* @param $children
* @return void
*/
public function setChildren(array $children) {
$this->children = $children;
}

/**
* @param RokMenuNodeBase $node
* @return void
*/
public function addChild(RokMenuNodeBase &$node) {
if (null == $this->children) {
$this->children = array();
}
$node->setParentRef($this);
$node->setLevel($this->getLevel()+1);
$this->children[$node->getId()] = $node;
}

/**
* @return bool
*/
public function hasChildren() {
return (count($this->children)>0)?true:false;
}

/**
* @return array
*/
public function &getChildren() {
return $this->children;
}

/**
* @param $node_id
* @return bool
*/
public function removeChild($node_id) {
if (array_key_exists($node_id, $this->children)) {
unset($this->children[$node_id]);
return true;
}
return false;
}
}
}