code: def relevant_issues(issues, after):
      
      logging.info('finding relevant issues after {}...'.format(after))
      seen = set()
      for issue in issues:
          if relevent_issue(issue, after) and issue['title'] not in seen:
              seen.add(issue['title'])
              yield issue
docs: Yields relevant closed issues (closed after a given datetime) given a list of issues.