property_name = "google calendar event id"
property_type = 'String'
-exchangelib.CalendarItem.register('gcal_link',ex_gcal_link)
+try:
+ exchangelib.CalendarItem.get_field_by_fieldname('gcal_link')
+except ValueError:
+ exchangelib.CalendarItem.register('gcal_link',ex_gcal_link)
#useful if you want to replay an event
def drop_from_ex_cache(itemid):