protected function redirectToStep( $step )
    {
        $routeMatch = $this->getEvent()
                           ->getRouteMatch();

        return $this->redirect()
                    ->toRoute( $routeMatch->getMatchedRouteName(),
                               ArrayUtils::merge(
                                   $routeMatch->getParams(),
                                   array( 'step' => $step )
                               ) );
    }