`Routing` folder not present inside `Drupal\Core\` I am trying to port a module from D7 to D8.

Since hook_help() uses routes instead of paths in D8, so the line use Drupal\Core\Routing\RouteMatchInterface; is added at the beginning of the code as mentioned on this page.

But the thing is that no folder named routing exists inside my Drupal\Core\.

Questions.


Am I supposed to add that folder myself? 
How will I configure
    RouteMatchInterface file.
That is the namespace. It's actual location in the file system is /core/lib/Drupal/Core/Routing. The autoloader knows where to look via the namespace.