protected function initializeBundleSelection(array $attr)
    {

        try {
            // try to load the product bundle option SKU/ID
            $parentProductId= $this->mapSku($this->getValue(ColumnKeys::BUNDLE_PARENT_SKU));
        } catch (\Exception $e) {
            throw $this->wrapException(array(ColumnKeys::BUNDLE_PARENT_SKU), $e);
        }

        try {
            // try to load the product ID
            $productId = $this->mapSku($this->getValue(ColumnKeys::BUNDLE_VALUE_SKU));
        } catch (\Exception $e) {
            throw $this->wrapException(array(ColumnKeys::BUNDLE_PARENT_SKU), $e);
        }

        // load the actual option ID
        $optionId = $this->getLastOptionId();

        // try to load the bundle selection with the passed option/product/parent product ID
        if ($entity = $this->loadBundleSelection($optionId, $productId, $parentProductId)) {
            return $this->mergeEntity($entity, $attr);
        }

        // simply return the attributes
        return $attr;
    }