A state node for [LimboHSM] that hosts a [BehaviorTree]. BTState is a [LimboState] node that manages a [BehaviorTree] to provide behavior logic for the state. It instantiates and runs the [BehaviorTree] resource, dispatching a state machine event upon [code]SUCCESS[/code] or [code]FAILURE[/code]. Event names are customizable through [member success_event] and [member failure_event]. For further details on state machine events, see [method LimboState.dispatch]. Returns the root task of the instantiated behavior tree. A [BehaviorTree] resource that defines state behavior. HSM event that will be dispatched when the behavior tree results in [code]FAILURE[/code]. See [method LimboState.dispatch]. HSM event that will be dispatched when the behavior tree results in [code]SUCCESS[/code]. See [method LimboState.dispatch].