code: public function save(CacheItemInterface $item)
      {
          $item->setIsHit(true);
          
          $this->data[$item->getKey()] = $item;
          
          return true;
      }
docs: Persists a cache item immediately.
  
  @param CacheItemInterface $item
  The cache item to save.
  
  @return bool True if the item was successfully persisted. False if there was an error.