get
Asynchronous get OverlayItem preview EXTENDED data (dynamic data that needs to be downloaded) as parameters list.
Return
GemError.NoError on success, GemError.InvalidInput if no listener specified, GemError.CouldNotStart if the request couldn't be started, GemError.NotSupported if called even though hasPreviewExtendedData returned false, GemError.General in any other error case.
Parameters
list
The list that will be populated with the preview extended data once it is downloaded.
listener
Progress listener which is MANDATORY.