public java.lang.String getOutputGcsUri() {
      java.lang.Object ref = outputGcsUri_;
      if (!(ref instanceof java.lang.String)) {
        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        outputGcsUri_ = s;
        return s;
      } else {
        return (java.lang.String) 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 outputGcsUri.
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/SynthesizeLongAudioRequest.java