The class is part of the QSF (examples site) demo project. It is not natively distributed with the RadCalendar control. I am attaching the calendar example project. It may not work outside the QSF or at least I have not tested it but more important you can find the classes you refer there in the Common folder. I hope this will help you. We will also add the files in the 'view source' mode of the example in the online examples.
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