Bridge/Symfony/Serializer/Normalizer/CustomerGroupNormalizer.php
public function normalize($group, $format = null, array $context = [])
    {
        if ($format === 'csv' && $this->contextHasGroup('TableExport', $context)) {
            return (string)$group;
        }

        return parent::normalize($group, $format, $context);
    }
public function normalize($group, $format = null, array $context = [])
    {
        if ($format === 'csv' && $this->contextHasGroup('TableExport', $context)) {
            return (string)$group;
        }

        return parent::normalize($group, $format, $context);
    }
@inheritdoc

@param CustomerGroupInterface $group