public override SequenceDiagramViewModel VisitNote([NotNull] NoteContext context)
{
// Extract actors
ActorViewModel[] actors = GetActors(context.actor(), context.actorPair());
if (actors == null || actors.Any(a => a == null))
{
m_errorListener.GrammarError("Notes must be declared relative to an actor. e.g. Note left of A: Message");
return(null);
}
// Extract placement of note
SequenceNotePlacement placement = GetPlacement(context.placement());
// Extract the note's message
string message = GetMessage(context.message());
// Combine into a note
SequenceDiagram.AddNote(actors, placement, message);
return(SequenceDiagram);
}