If you are trying to get to grips with Dependency Injection in Drupal 8 then here is a walk-through of how I applied it in one of my Drupal 8 test projects.

I have a project I have been using to investigate Drupal 8 since alpha10 which has been invaluable in my learning process. But as a result, some of my code is over 2 years old and written when I barely had a grasp of Drupal 8 concepts.

In the past week a very old @todo jumped out to me: