public class EventStoreInterface{
// this will be our virtual class
// it will contains abstract functions/methods addOccation, checkOccation, etc
}

class CSVEventStore: public EventStoreInterface{
// We have inherited EventStoreInterface
// Here we have implementation of functions like addOccation, checkOccation, etc specifically for CSV
}

class XMLEventStore: public EventStoreInterface{
// We have inherited EventStoreInterface
// Here we have implementation of functions like addOccation, checkOccation, etc specifically for XML
}


// Now the main function would look something like this
int main(int argc, char *argv[])
{
	if(argv[1] == "xml")
	{
		EventStoreInterface Event = new XMLEventStore;
	}
	if(argv[1] == "csv")
	{
		EventStoreInterface Event = new CSVEventStore;
	}
/* Now we will pass the "Event" to our gui(MainWindow) and will call the methods of it, which will hide whether the method of XMLEventStore is called or of CSVEventStore.
*/
}

// This type of implementation will hide the data storage from the rest of the application. The business layer / UI also will not know which backend is used.