public function objLabels()
    {
        if ($this->objLabels === null) {
            $objLabels = [];
            $proto = $this->proto();
            $objMetadata = $proto->metadata();
            if (isset($objMetadata['labels']) && !empty($objMetadata['labels'])) {
                $objLabels = $objMetadata['labels'];
                array_walk($objLabels, function(&$value) {
                    $value = $this->translator()->translation($value);
                });
                $this->objLabels = $objLabels;
            }
        }

        return $this->objLabels;
    }