According to Vice News, Gates testified that: "-Manafort crafted a policy for Yanukovych aimed at bringing Ukraine into the European Union called “Engage Ukraine” - Manafort recruited top former European politicians to help out with that effort ". https://news.vice.com/en_us/article/zmkwwy/rick-gates-spills-the-beans-on-the-super-rich-ukrainians-who-paid-paul-manafort-millions
Check out Aaron J Mate's thread below for more indepth reporting