Hong Kong CNN  —  Lin En could have easily reached his destination in six hours had he caught a flight. But during a trip earlier this year, the 23-year-old opted for a bus ride that took three days to cross from Xinjiang, in China’s northwest, to Astana, Kazakhstan’s capital. Make no mistake. There was no premium in-bus entertainment, first-class dining or specially designed ergonomic seats on offer that made the ride particularly enjoyable. The journey was a grueling one. The tens of hours