This demonstration configuration is:
Have a look at the current LSC cache: The contents of this page and "Link 1" are cached already, while pre-fetching "Link 2" has been disabled, and so its contents are missing in the cache for now. As soon as you open "Link 2", LSC will cache the content and hold it as long as the cache version wasn't changed. You're welcome to open the JavaScript console and try the functionality that is described on the projects GitHub page. Use the browsers forward and back buttons to see how and when the history index changes.
Links:
Browser history index: