Translations:Draft Upgrade/10/en


 * contains the objects to be upgraded. It is either a single object or a list of objects.
 * If is  the source objects are deleted.
 * forces a certain way of upgrading by calling a specific internal function. It can be:, , , , , , , , , , , or.
 * is returned. It is a list containing two lists: a list of new objects and a list of objects to be deleted. If is  the second list is empty.