（2）虚拟线程开始执行 getCache()，执行到 Thread.sleep(50) 时，JVM 检测到这个操作会阻塞，于是：
When Hull Kingston Rovers play Leeds Rhinos in Las Vegas on Saturday night, they will do so as domestic treble winners and world club champions. The club’s chief executive, Paul Lakin, explains how they made it this far and what they want to achieve next.
。新收录的资料对此有专业解读
"Some men when they have a midlife crisis buy a Lamborghini or grow a ponytail, but me - I want my very own castle," said Carr who is approaching 50.
"Do it slowly, do it right but let's get on with it," she said. "We have been stagnating at these very low recycling rates for far too long."