public override SequenceDiagramViewModel VisitSignal([NotNull] SignalContext context)
{
var actorA = GetActor(context.actor(0));
var actorB = GetActor(context.actor(1));
if (actorA == null || actorB == null)
{
m_errorListener.GrammarError("Signals must occur between two actors. e.g. a->b: pew pew");
return(SequenceDiagram);
}
var signalType = GetSignalType(context.signalType());
var message = GetMessage(context.message());
SequenceDiagram.AddSignal(actorA, signalType.Item1, signalType.Item2, actorB, message);
return(SequenceDiagram);
}