docs: def _check_transition_validity(self, check_transition):
          """ Transition of BarrierConcurrencyStates must least fulfill the condition of a ContainerState.
          Start transitions are forbidden in the ConcurrencyState
  
          :param check_transition: the transition to check for validity
          :return:
          """
          valid, message = super(PreemptiveConcurrencyState, self)._check_transition_validity(check_transition)
          if not valid:
              return False, message
  
          # Only transitions to the parent state are allowed
  
          if check_transition.to_state != self.state_id:
              return False, "Only transitions to the parent state are allowed"
  
          return True, message