public final UnaryCallable<BatchTranslateDocumentRequest, Operation>
      batchTranslateDocumentCallable() {
    return stub.batchTranslateDocumentCallable();
  }
Translates a large volume of document in asynchronous batch mode. This function provides
real-time output as the inputs are being processed. If caller cancels a request, the partial
results (for an input file, it's all or nothing) may still be available on the specified output
location.

<p>This call returns immediately and you can use google.longrunning.Operation.name to poll the
status of the call.

<p>Sample code:

<pre>{@code
// This snippet has been automatically generated and should be regarded as a code template only.
// It will require modifications to work:
// - It may require correct/in-range values for request initialization.
// - It may require specifying regional endpoints when creating the service client as shown in
// https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
try (TranslationServiceClient translationServiceClient = TranslationServiceClient.create()) {
  BatchTranslateDocumentRequest request =
      BatchTranslateDocumentRequest.newBuilder()
          .setParent(LocationName.of("[PROJECT]", "[LOCATION]").toString())
          .setSourceLanguageCode("sourceLanguageCode1645917472")
          .addAllTargetLanguageCodes(new ArrayList<String>())
          .addAllInputConfigs(new ArrayList<BatchDocumentInputConfig>())
          .setOutputConfig(BatchDocumentOutputConfig.newBuilder().build())
          .putAllModels(new HashMap<String, String>())
          .putAllGlossaries(new HashMap<String, TranslateTextGlossaryConfig>())
          .putAllFormatConversions(new HashMap<String, String>())
          .setCustomizedAttribution("customizedAttribution557650238")
          .setEnableShadowRemovalNativePdf(true)
          .setEnableRotationCorrection(true)
          .build();
  ApiFuture<Operation> future =
      translationServiceClient.batchTranslateDocumentCallable().futureCall(request);
  // Do something.
  Operation response = future.get();
}
}</pre>
java-translate/google-cloud-translate/src/main/java/com/google/cloud/translate/v3beta1/TranslationServiceClient.java