This file contains data to test (CSS against) a plethora of markup that is commonly used in WDS WordPress themes.
In the past we've used tools like: WPTest.io, WPfill.me, and WordPress.org's Theme Unit Test. We'll probably try to pick from each, and make a super-duper theme unit test (now known as TUT).
PRs are welcome.
Go to Tools > Import and install the WordPress Importer (if not already installed). Import, and profit.