With the DI2 electronic shifting my understanding is that the LBS can program it when you purchase it. Does the bike come with the programmer to do at home? Do I need the programmer or should I get it? Or does it have to be done professionally at the shop? Due to inventory I am not getting my bike at a store close to me, so was just trying to figure out what I need to do in case I want to ever change the settings, etc. and if it comes with the programmer or I need to purchase it. Any input is appreciated! Thank you.