Stock Delivered But Not Billed

https://raw.githubusercontent.com/frappe/erpnext/develop/erpnext/stock/doctype/delivery_note/delivery_note.py

Is this feature not backported to current v16 erpnext? Because it seems that the feature available in v17 develop of erpnext. If haven’t backported i am planning to copy some of the codes and make it work right now because the accountant needs the feature for perpetual inventory.