public function getStepStore( $step )
    {
        $store  = $this->getStore();
        $steps  = $store['steps'];
        $step   = (string) $step;

        if ( empty( $steps[$step] ) )
        {
            $steps[$step]   = array();
            $store['steps'] = $steps;
        }

        return $steps[$step];
    }