protected function formatGroupHeader(
        EnvironmentInterface $environment,
        ModelInterface $model,
        PropertyInterface $property,
        $groupingMode,
        $groupingLength
    ) {
        $evaluation = $property->getExtra();

        if (!$evaluation['multiple'] && ('checkbox' === $property->getWidgetType())) {
            return $this->formatCheckboxOptionLabel($model->getProperty($property->getName()));
        }
        if (GroupAndSortingInformationInterface::GROUP_NONE !== $groupingMode) {
            return $this->formatByGroupingMode($groupingMode, $groupingLength, $environment, $property, $model);
        }

        $value = ViewHelpers::getReadableFieldValue($environment, $property, $model);

        if (isset($evaluation['reference'])) {
            $remoteNew = $evaluation['reference'][$value];
        } elseif (\array_is_assoc($property->getOptions())) {
            $options   = $property->getOptions();
            $remoteNew = $options[$value];
        } else {
            $remoteNew = $value;
        }

        if (\is_array($remoteNew)) {
            $remoteNew = $remoteNew[0];
        }

        if (empty($remoteNew)) {
            $remoteNew = '-';
        }

        return $remoteNew;
    }