EventSummaryCallback
A callback invoked when event summaries are ready.
The summary parameter is the IntPtr key used by GetSummary(IntPtr) to get the proper EventSummary results available for that key.
The userData parameter is the value set when subscribing with Subscribe(String,EventSummaryCallback,IntPtr)).
Any memory held by the EventSummary is invalidated when the callback returns.
Parameters
summary : IntPtr : IntPtr used by GetSummary(IntPtr) to get the EventSummary.
userData : IntPtr : IntPtr is the value set with Subscribe(String,EventSummaryCallback,IntPtr).