public static string DiagName(this ICallRouter callRouter, DiagContextInternal ctx)
        {
            var name = $"<{callRouter.GetObjectId(ctx)}";

            if (ctx.TryGetSubstituteForRouter(callRouter, out object substitute))
            {
                name += $"#{substitute.SubstituteId(ctx)}";
            }

            return($"{name}>");
        }