public com.google.protobuf.ByteString getModelBytes() {
      java.lang.Object ref = model_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        model_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. The `model` type requested for this translation.

The format depends on model type:

- AutoML Translation models:
  `projects/{project-number-or-id}/locations/{location-id}/models/{model-id}`

- General (built-in) models:
  `projects/{project-number-or-id}/locations/{location-id}/models/general/nmt`,


If not provided, the default Google model (NMT) will be used for
translation.
</pre>

<code>string model = 6 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for model.
java-translate/proto-google-cloud-translate-v3beta1/src/main/java/com/google/cloud/translate/v3beta1/TranslateDocumentRequest.java