docs: def randomEarlyShared(store, role):
      """
      If there are no explicitly-published public index pages to display, find a
      shared item to present to the user as first.
      """
      for r in role.allRoles():
          share = store.findFirst(Share, Share.sharedTo == r,
                                  sort=Share.storeID.ascending)
          if share is not None:
              return share.sharedItem
      raise NoSuchShare("Why, that user hasn't shared anything at all!")