code: public function getNotCachedAttributes($key, array $attributes = ['*'])
      {
          if (!$this->has($key)) {
              return $attributes;
          }
          $cachedAttributes = $this->cache[$key]['attributes'];
          return $cachedAttributes == ['*'] ? [] : array_diff($attributes, $cachedAttributes);
      }
docs: Return the difference between given attributes and attributes which are already cached.
  
  @param mixed $key
  @param array $attributes
  @return array