code: def fetch_action_restriction(self, reftrack, action):
          
          inter = self.get_typ_interface(reftrack.get_typ())
          d = {'reference': inter.is_reference_restricted, 'load': inter.is_load_restricted,
               'unload': inter.is_unload_restricted, 'replace': inter.is_replace_restricted,
               'import_reference': inter.is_import_ref_restricted, 'import_taskfile': inter.is_import_f_restricted,
               'delete': inter.is_delete_restricted,}
          f = d.get(action, None)
          if not f:
              return True
          else:
              return f(reftrack)
docs: Return wheter the given action is restricted for the given reftrack
  
          available actions are:
  
             ``reference``, ``load``, ``unload``, ``replace``, ``import_reference``, ``import_taskfile``, ``delete``
  
          If action is not available, True is returned.
  
          :param reftrack: the reftrack to query
          :type reftrack: :class:`Reftrack`
          :param action: the action to check.
          :type action: str
          :returns: True, if the action is restricted
          :rtype: :class:`bool`
          :raises: None