Finite\StateMachine\StateMachine::addTransition PHP Method

    public function addTransition($transition, $initialState = null, $finalState = null)
    {
        if ((null === $initialState || null === $finalState) && !$transition instanceof TransitionInterface) {
            throw new \InvalidArgumentException('You must provide a TransitionInterface instance or the $transition, ' . '$initialState and $finalState parameters');
        }
        // If transition isn't a TransitionInterface instance, we create one from the states date
        if (!$transition instanceof TransitionInterface) {
            try {
                $transition = $this->getTransition($transition);
            } catch (Exception\TransitionException $e) {
                $transition = new Transition($transition, $initialState, $finalState);
            }
        }
        $this->transitions[$transition->getName()] = $transition;
        // We add missings states to the State Machine
        try {
            $this->getState($transition->getState());
        } catch (Exception\StateException $e) {
            $this->addState($transition->getState());
        }
        foreach ($transition->getInitialStates() as $state) {
            try {
                $this->getState($state);
            } catch (Exception\StateException $e) {
                $this->addState($state);
            }
            $state = $this->getState($state);
            if ($state instanceof State) {
                $state->addTransition($transition);
            }
        }
    }

    protected function setUp()
    {
        $this->env = new \Twig_Environment(
            new \Twig_Loader_Array(
                array(
                    'state'       => '{{ finite_state(object) }}',
                    'transitions' => '{% for transition in finite_transitions(object) %}{{ transition }}{% endfor %}',
                    'properties'  => '{% for property, val in finite_properties(object) %}{{ property }}{% endfor %}',
                    'has'         => '{{ finite_has(object, property) ? "yes" : "no" }}',
                    'can'         => '{{ finite_can(object, transition) ? "yes" : "no" }}'
                )
            )
        );

        $container = new \Pimple(array(
            'state_machine' => function() {
                $sm =  new StateMachine;
                $sm->addState(new State('s1', State::TYPE_INITIAL, array(), array('foo' => true, 'bar' => false)));
                $sm->addTransition('t12', 's1', 's2');
                $sm->addTransition('t23', 's2', 's3');

                return $sm;
            }
        ));

        $this->context = new Context(new PimpleFactory($container, 'state_machine'));;
        $this->env->addExtension(new FiniteExtension($this->context));
    }