purpose of commerce_addressbook_build_form_id_list() ?

Hi,

What is the exact purpose of the function commerce_addressbook_build_form_id_list(), other than attaching the commerce_addressbook.js file to the form?
The variable $fieldnames is a string on line 56, and threated as an array below, so I suppose this code is obsolete? The Drupal.settings.addressfield_names is not used in the Javascript file anyway...

If this is true, can we clean up this function and perhaps give it a more descriptive name? This will make it easier to understand what's going on in the module :)