This question is a bit different from the average "How do I access the members of a group invited to a calendar event". I have been using the AdminSDK/Directory API to do that and it works well.
My scenario is this: I have 2 different calendar items 6 months apart (one in the past and one in the future). The same google group has been invited to these calendar events. In the past 3 months, membership of that group has changed. When I look at the 2 events in GCal and I click the arrow next to the group name, the members are listed correctly, in that it knows a different set of group members were invited to the event in the past than the one in the future. If I change the group members, it will be reflected on the calendar item in the future but not the one in the past. (as I would expect)
My question is, how do I access the historical attendee information of the past calendar event via the API (short of scouring everyone's personal calendars).
