private function addChildSku(&$parentData, $relation)
    {
        if (isset($parentData['sku']) && !is_array($parentData['sku'])) {
            $parentData['sku'] = [$parentData['sku']];
        }

        $parentData['sku'][] = $relation['sku'];
        $parentData['sku'] = array_unique($parentData['sku']);
    }
private function addChildSku(&$parentData, $relation)
    {
        if (isset($parentData['sku']) && !is_array($parentData['sku'])) {
            $parentData['sku'] = [$parentData['sku']];
        }

        $parentData['sku'][] = $relation['sku'];
        $parentData['sku'] = array_unique($parentData['sku']);
    }
private function addChildSku ( & $ parentData , $ relation ) { if ( isset ( $ parentData [ 'sku' ] ) && ! is_array ( $ parentData [ 'sku' ] ) ) { $ parentData [ 'sku' ] = [ $ parentData [ 'sku' ] ] ; } $ parentData [ 'sku' ] [ ] = $ relation [ 'sku' ] ; $ parentData [ 'sku' ] = array_unique ( $ parentData [ 'sku' ] ) ; }
Append SKU of children product to the parent product index data.

@param array $parentData Parent product data.
@param array $relation   Relation data between the child and the parent.
Append SKU of children product to the parent product index data .