public interface IPlayerLocator	{ ... }

	public class Enemy
	{
		public bool WithinDistance (){ ... }
		public bool HasTarget () { ... }
		public Result MoveTowards () { ... }
		public Result SelectTarget () { ... }
		public Result HitTarget () { ... } 
	}	
	
	public class EnemySituation
	{
		public IPlayerLocator Service;
		public Enemy Individual;
	}

	public abstract class BaseEnemyAI : Step, IBlackboardNode<Enemy>
	{
		#region IBlackboardNode implementation
		public Blackboard<Enemy> Board { get; set; }
		#endregion
	}	
	
	// initialise tree build
	var dictionary = new TreeDictionary();
	var builder = new BlackboardTreeBuilder<Enemy>(new TreeBuilder(), dictionary);

	// gererate a behavior tree
	builder
		.Sequence()
			.Begin ()
			.Selector()
				.Begin ()
					.IsTrue((e) => e.HasTarget())
					.Selector ()
					.Begin ()
						.Step((e) => e.SelectTarget())
					.End ()
				.End ()
			.Selector()
				.Begin ()
					.IsTrue((e) => e.WithinDistance())
					.Selector ()
					.Begin ()
						.Step((e) => e.MoveTowards())
					.End ()
				.End()
			.End ()
			.Step ((e) => e.HitTarget())
		.End ()
	.BuildAndRegisterAs<BaseEnemyAI>();

	var topBuilder = new BlackboardTreeBuilder<EnemySituation>(new TreeBuilder(), dictionary);
	
	// generate tree as a stub for an BaseEnemyAI implementation
	var tree = topBuilder
		.UseStub<BaseEnemyAI, Enemy>()
		.Build();

	var walker = new NodeWalker(tree);
	walker.AddBlackboard<EnemySituation>(new Blackboard<EnemySituation>{ Context = new EnemySituation()});
	walker.AddDependentBlackboard<EnemySituation, Enemy>((es) => {return es.Individual;});