code: func (cache *Cache) IterateCachedStorage(address crypto.Address,
  	consumer func(key, value binary.Word256) error) error {
  	accInfo, err := cache.get(address)
  	if err != nil {
  		return err
  	}
  	accInfo.RLock()
  	// Try cache first for early exit
  	for key, value := range accInfo.storage {
  		if err := consumer(key, value); err != nil {
  			accInfo.RUnlock()
  			return err
  		}
  	}
  	accInfo.RUnlock()
  	return err
  }
docs: // Iterates over all cached storage items first in cache and then in backend until consumer returns true for 'stop'