Finite\StateMachine\StateMachine::findStateWithProperty PHP Method

    public function findStateWithProperty($property, $value = null)
    {
        return array_keys(array_map(function (State $state) {
            return $state->getName();
        }, array_filter($this->states, function (State $state) use($property, $value) {
            if (!$state->has($property)) {
                return false;
            }
            if (null !== $value && $state->get($property) !== $value) {
                return false;
            }
            return true;
        })));
    }