private function getStateShape(State $state)
 {
     switch ($state->getType()) {
         case State::TYPE_INITIAL:
             return 'doublecircle';
         default:
             return 'circle';
     }
 }
 /**
  * @param StateInterface $state
  * @param StateMachineInterface $stateMachine
  *
  * @return array
  */
 private function getDefaultNodeAttributes(StateInterface $state, StateMachineInterface $stateMachine)
 {
     return ['shape' => $state->getType() != StateInterface::TYPE_NORMAL ? 'doublecircle' : 'circle', 'label' => $state->getName()];
 }