code: func (q *lockBasedQueryExecutor) GetPrivateDataMetadataByHash(namespace, collection string, keyhash []byte) (map[string][]byte, error) {
  	return q.helper.getPrivateDataMetadataByHash(namespace, collection, keyhash)
  }
docs: // GetPrivateDataMetadataByHash implements method in interface `ledger.QueryExecutor`