def update_documents_batch(self, batch: List[VespaDocument],
                               schema: str,
                               concurrency: Optional[int] = None,
                               timeout: int = 60,
                               vespa_id_field: str = "marqo__id") -> UpdateDocumentsBatchResponse:
        """
        Partial update documents in batch concurrently.

        If the document does not exist, it will not be created and an error for that document will be
        returned in the response.

        Args:
            batch: A list of documents to update
            schema: schema name
            concurrency: Number of concurrent delete requests, can be configured by environment variable
                VESPA_PARTIAL_UPDATE_POOL_SIZE
            timeout: Timeout in seconds per request
            vespa_id_field: The field name of the vespa document id under the fields dictionary

        Returns:
            A UpdateDocumentsBatchResponse object
        """

        if not batch:
            return UpdateDocumentsBatchResponse(responses=[], errors=False)

        if concurrency is None:
            concurrency = self.partial_pool_size

        batch_response = conc.run_coroutine(
            self._update_documents_batch_async(batch, schema, concurrency, timeout, vespa_id_field)
        )

        return batch_response

        Partial update documents in batch concurrently.

        If the document does not exist, it will not be created and an error for that document will be
        returned in the response.

        Args:
            batch: A list of documents to update
            schema: schema name
            concurrency: Number of concurrent delete requests, can be configured by environment variable
                VESPA_PARTIAL_UPDATE_POOL_SIZE
            timeout: Timeout in seconds per request
            vespa_id_field: The field name of the vespa document id under the fields dictionary

        Returns:
            A UpdateDocumentsBatchResponse object
        
src/marqo/vespa/vespa_client.py