public override void PostWalkSignalTrigger(SignalTriggerSyntax signalTriggerSyntax) { 
			MethodsCalled["PostWalkSignalTrigger"]=true;
		}
        public override void VisitSignalTrigger(SignalTriggerSyntax signalTriggerSyntax) {

            if (signalTriggerSyntax.IdentifierOrStringList == null) {
                return;
            }

            foreach(var signal in signalTriggerSyntax.IdentifierOrStringList) {
                var location = signal.GetLocation();
                if(location != null) {
                    var trigger = new SignalTriggerSymbol(signal.Text, location, signal);
                    _triggers.Add(trigger);
                }
            }
        }
		// SignalTriggerSyntax
		public override bool WalkSignalTrigger(SignalTriggerSyntax signalTriggerSyntax) { 
			MethodsCalled["WalkSignalTrigger"]=true;
			return true; 
		}