public function initialize($currentStepSlug)
{
try {
$this->currentStep = $this->findStepBySlug($currentStepSlug);
$this->currentStepIndex = $this->stepIndex($this->currentStep->getId());
} catch (StepNotFoundException $e) {
$this->currentStep = $this->firstStep();
$this->currentStepIndex = 0;
}
}