private static void ReadMarker(this XContainer topic, NodeBase node) { var markerRefs = topic.Element(Namespaces.Content("marker-refs")); if (markerRefs == null) { return; } var markerId = markerRefs.Elements(Namespaces.Content("marker-ref")).Select(x => x.Attribute("marker-id")?.Value).FirstOrDefault(x => x != null); if (string.IsNullOrWhiteSpace(markerId)) { return; } var icon = MarkerMapping.ResolveMindapp(markerId); if (icon != null) { node.ChangeIconTransactional(new KeyIcon(icon)); } }