var behaviorTree = BehaviorGraph.ChainForThis code sets up a behavior tree for an NPC that starts in the idle state, sees a player, chases them until the player is lost, and then goes back to the idle state. The package library for BehaviorGraph is "BehaviorTree.FluentBuilder" which provides a fluent API for defining behavior trees in C#.() .Do () // NPC is idle .Until () // NPC sees a player .Do () // NPC chases the player .Until () // NPC loses sight of the player .GoTo () // NPC returns to idle state .Finish();