sses also provides many additional features which comes in handy and saves time. The main class doing the work behind the scenes is Qtilities::Core::Observer. However this article will not look at the details of how things work, it will just show how to use the classes and build trees without worrying how it works in the background. The \ref page_observers article is a good place to start if you are interested in the details.

Table of contents:
- \ref tree_building_classes
- \ref lets_build_some_trees
  - 