I am going to make custom pos ticket, but I haven't posbox (and pos printer). So I am looking for a way to debug this changes. 

As I understand point_of_sale use different templates for usual ticket (<t t-name="PosTicket">) and for esc\pos ticket  ( <t t-name="XmlReceipt"> )

https://github.com/odoo/odoo/blob/master/addons/point_of_sale/static/src/xml/pos.xml

So I need some esc\pos emulator. I found something 

https://gitorious.org/screenticket/screenticket/

but it is not ready-to-use solution.