public function getHashContents()
    {
        if (is_array($this->_hashContents)) return $this->_hashContents;
        $this->_hashContents = array();
        if(!isset($this->_packageXml->contents->target)) {
            return $this->_hashContents;
        }
        foreach($this->_packageXml->contents->target as $target) {
            $targetUri = $this->getTarget()->getTargetUri($target['name']);
            $this->_getHashList($target, $targetUri);
        }
        return $this->_hashContents;
    }