I need to change the assignee when transitioning through the workflow. But if the review of the doc in each part of the workflow was to fail, I need to assign it back to the person who last reviewed/changed it. I know using a post-function I can change the assignee as it moves forward but if it moves backward then how do I assign the issue back to the last person who had it. I do not want to assign to the Reporter who was the person who originally created it.