Magento: Programmatically create associated products to a grouped one

magento

Solution

$products_links = Mage::getModel('catalog/product_link_api');
$products_links->assign ("grouped",$group_product_id,$simple_product_id);

http://docs.magentocommerce.com/Mage_Catalog/Mage_Catalog_Model_Product_Link_Api.html

looks good in Magento 1.6.2.0

Problem

How can I Programmatically create/link associated products to a grouped one ?? Thanks for help.

Original source