How to save Appointments?

I looked at the document here: https://docs.telerik.com/devtools/winforms/controls/scheduler/importing-and-exporting-appointments/export-to-a-custom-file

However that's not really the question I have.  How are appointments saved without data binding, to a file? The above example is how to save custom data to a file, but I'm trying to figure out how to save appointments that aren't custom.  I'd like to be able to write them out as JSON or something like that, and allow them to be imported that way as well.

I was able to get the list of events, but when I attempted to serialize them using Newtonsofts JSON, it throws an error. 

The error I get is: 

Newtonsoft.Json.JsonSerializationException: 'Self referencing loop detected for property 'Scheduler' with type 'Telerik.WinControls.UI.RadScheduler'. Path 'CultureInfoProvider.SchedulerInputBehavior'.'

Here is the code I was using to iterate over the appointments and attempt to serialize each appointment:

        Dim events As ISchedulerStorage(Of IEvent) = data.GetEventStorage()
        For Each ev As IEvent In events
            Dim jsonEvent As String = JsonConvert.SerializeObject(ev, Formatting.Indented)
        Next