Missing action hook

Hello,

I wanted to use the woocommerce_after_edit_attribute_fields hook (and its _add_ counterpart), which, in the latest version 2.6.9 of WooCommerce, is present on line #341 in includes/admin/class-wc-admin-attributes.php.
The strange thing is that these action hooks are missing in the production version actually used by WP: http://plugins.svn.wordpress.org/woocommerce/tags/2.6.9/includes/admin/class-wc-admin-attributes.php
It’s the same version 2.6.9 but the code is different. What is the reason for this? Am I missing something obvious?

Thanks in advance.