fn prepare_dml_batch_payload(
headers: &HeaderMap,
raw_dml_batch: RawDmlBatchRequest,
payload_schema: &PayloadSchema,
) -> Result<PreparedDmlBatch, String>fn prepare_dml_batch_payload(
headers: &HeaderMap,
raw_dml_batch: RawDmlBatchRequest,
payload_schema: &PayloadSchema,
) -> Result<PreparedDmlBatch, String>