public function buildersToUomsArray(array $builders)
    {
        $uoms = array();
        foreach ($builders as $builder) {
            foreach ($builder->getProduct()->getUoms() as $uom) {
                $uomArray = $this->uomToArray($uom);
                $uoms[$uomArray['uom_string']] = $uomArray;
            }
        }
        return $uoms;
    }