public function setStartState($stateId)
    {
        $state = $this->stateMachine->getState(StateMachine::STATE_INITIAL);
        if ($state === null) {
            $state = new InitialState(StateMachine::STATE_INITIAL);
            $this->stateMachine->addState($state);
        }

        $this->addTransition(StateMachine::STATE_INITIAL, $stateId, StateMachine::EVENT_START);
    }