def locateTimeline(profiles, txnId):
  """
  Performs a lookup of timeline object with txnId

  :param profiles: profiles holding a collection of timelines
  :param txnId: txnId of the timeline to lookup

  """
  for profile in profiles:
    for timeline in profile.current.timelineCollection:
      if timeline.txnId == txnId:
        return timeline
  return None