HARDtalk speaks to Zhang Xin, one of only 24 self-made female billionaires in the world. Hers is a true rags-to-riches story - as a teenager she worked in a sweat-shop in her native China, by her twenties she worked for Goldman Sachs and, disillusioned by Wall Street, she returned to China to make her fortune in property development. But what kind of China did she return to, a country heading for economic problems, or possibly an emerging democracy as well as an emerging super-power?