Retrieves a timeline event based on its ID and incident record.
See https://paws-r.github.io/docs/ssmincidents/get_timeline_event.html for full documentation.
ssmincidents_get_timeline_event(eventId, incidentRecordArn)[required] The ID of the event. You can get an event's ID when you create it, or by
using list_timeline_events.
[required] The Amazon Resource Name (ARN) of the incident that includes the timeline event.