code: def WriteHashBlobReferences(self, references_by_hash, cursor):
      
      values = []
      for hash_id, blob_refs in iteritems(references_by_hash):
        refs = rdf_objects.BlobReferences(items=blob_refs).SerializeToString()
        values.append({
            "hash_id": hash_id.AsBytes(),
            "blob_references": refs,
        })
      _Insert(cursor, "hash_blob_references", values)
docs: Writes blob references for a given set of hashes.