public Graph apply(Action act,Agent a) {
		switch(act.get_type()){
		case NoOp:
			caseNoOp(a);
			break;
		case Traverse:
			caseTraverse(a, act);
			break;
		}
		if(GameType.ZeroSum==this.gt)
			_agents.get(1).setCost(-_agents.get(0).getCost());
		return this;
	}