Behaviour Tree framework for Godot coded in GDScript.
A tutorial related to this code is here: Godot Behaviour Tree
When the project is "Played", the main scene is the Test scene that runs through the tests of the available BT Nodes displaying results visually in a list.
The BehaviourTree Scene is just to contain all of the available BT Nodes. These appear as Nodes in the Editor (because they are named classes with Icons) that may be added to your Behaviour Tree to build it out with the Nodes and develop your own Leaf Nodes to suit your application/game.