COS:

• Show change history every time a new issue is attached or detached from the Epic
• When multiple issues are attached to an epic at once log just one change history entry
• When multiple issues are detached from an epic at once log just one change
• Can't use the Epic Link field (because that's always from Child to Parent)

Testing Notes

Q: Which events are tracked in the history? Are there any special events for issues that are either not tracked or different for epics?
A: Just adding / removing issues, no special events.

Q: Can you backdate changes?
A: No

Q: What happens to the change history for completing an epic and reopening it?
A: History of added / removed issues shouldn't be affected.

Q: What happens to the change history when estimating stories in that epic?
A: Nothing