Part of learning Drupal’s API is learning about “what’s in the pantry.” In Drupal 8, that pantry is configured quite a bit differently than before. Instead of getting the whole warehouse of Drupal functions on every page load, functions—well, now methods—are contained in objects which are defined by classes. Most, if not all, of these classes, which exist in their own PHP files, can be extended and many of them are specifically designed to be extended. These extensible classes are the pantries. They contain properties and methods that we can just use in the classes that extend them. When we extend these classes, we need to make sure we peek inside to see what’s available before we go elsewhere for something that might already be in the cupboard.