public Builder mergeGcsDestination(com.google.cloud.translate.v3.GcsOutputDestination value) {
      if (gcsDestinationBuilder_ == null) {
        if (destinationCase_ == 1
            && destination_
                != com.google.cloud.translate.v3.GcsOutputDestination.getDefaultInstance()) {
          destination_ =
              com.google.cloud.translate.v3.GcsOutputDestination.newBuilder(
                      (com.google.cloud.translate.v3.GcsOutputDestination) destination_)
                  .mergeFrom(value)
                  .buildPartial();
        } else {
          destination_ = value;
        }
        onChanged();
      } else {
        if (destinationCase_ == 1) {
          gcsDestinationBuilder_.mergeFrom(value);
        } else {
          gcsDestinationBuilder_.setMessage(value);
        }
      }
      destinationCase_ = 1;
      return this;
    }
<pre>
Google Cloud Storage destination to write the output.
</pre>

<code>.google.cloud.translation.v3.GcsOutputDestination gcs_destination = 1;</code>
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/DatasetOutputConfig.java