code: def CheckHashes(hash_ids):
    
    return {
        k: bool(v)
        for k, v in data_store.REL_DB.ReadHashBlobReferences(hash_ids).items()
    }
docs: Checks if files with given hashes are present in the file store.
  
    Args:
      hash_ids: A list of SHA256HashID objects.
  
    Returns:
      A dict where SHA256HashID objects are keys. Corresponding values
      may be False (if hash id is not present) or True if it is not present.