public com.google.protobuf.ByteString getOutputGcsUriBytes() {
      java.lang.Object ref = outputGcsUri_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        outputGcsUri_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Required. Specifies a Cloud Storage URI for the synthesis results. Must be
specified in the format: `gs://bucket_name/object_name`, and the bucket
must already exist.
</pre>

<code>string output_gcs_uri = 4 [(.google.api.field_behavior) = REQUIRED];</code>

@return The bytes for outputGcsUri.
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/SynthesizeLongAudioRequest.java