public Then(When when, string step) {
			this.when = when;
			this.step = step;
			this.duration = "1 frame";
		}
		public Then(When when, string step, string duration) {
			this.when = when;
			this.step = step;
			this.duration = duration;
		}
		public When When(string step) {
			when = new When(step);
			return when;
		}