public function add_module($title) {
        $this->resource_count++;
        $resource_str = str_pad($this->resource_count.'',6,'0',STR_PAD_LEFT);
        $identifier = 'T_'.$resource_str;

        $xpath = new \DOMXpath($this);

        $items = $xpath->query(CC::item_xpath)->item(0);
        $module = $this->add_child_ns(CC::CC_1_1_CP, $items, 'item', null, array('identifier' => $identifier));
        $new_title = $this->add_child_ns(CC::CC_1_1_CP, $module, 'title', $title);
        return $module;
    }