code: def reftrack_restricted_data(rt, role, attr):
      
      if role == QtCore.Qt.DisplayRole:
          if rt.is_restricted(getattr(rt, attr, None)):
              return "Restricted"
          else:
              return "Allowed"
docs: Return the data for restriction of the given attr of the given reftrack
  
      :param rt: the :class:`jukeboxcore.reftrack.Reftrack` holds the data
      :type rt: :class:`jukeboxcore.reftrack.Reftrack`
      :param role: item data role
      :type role: QtCore.Qt.ItemDataRole
      :returns: data for the restriction
      :rtype: depending on role
      :raises: None