From http://techbus.safaribooksonline.com/book/programming/javascript/9781593272821/data-structures-objects-and-arrays/the_problem_colon_aunt_emily_apostrophy#X2ludGVybmFsX0h0bWxWaWV3P3htbGlkPTk3ODE1OTMyNzI4MjElMkZ0aGVfc2FkX3N0b3J5X29mX3RoZV9yZWNsdXNlJnF1ZXJ5PQ==