/**
  * {@inheritdoc}
  */
 public function save(\Magento\Quote\Api\Data\CartInterface $quote)
 {
     if ($quote->getId()) {
         $currentQuote = $this->get($quote->getId(), [$quote->getStoreId()]);
         foreach ($currentQuote->getData() as $key => $value) {
             if (!$quote->hasData($key)) {
                 $quote->setData($key, $value);
             }
         }
     }
     $this->getSaveHandler()->save($quote);
     unset($this->quotesById[$quote->getId()]);
     unset($this->quotesByCustomerId[$quote->getCustomerId()]);
 }