Magento - 无法在可下载的产品中找到插入操作

Hi was looking for the action that makes the insert when i click on downloadable product

The insert its made in table downloadable_link; how magento does the insert process to add a field in the current table ?

i founded in ww\magento\app\code\local\Mage\Downloadable\Block\Adminhtml\Catalog\Product\Edit\Tab\Downloadable\Links.php