public int getTimepointsCount() {
      if (timepointsBuilder_ == null) {
        return timepoints_.size();
      } else {
        return timepointsBuilder_.getCount();
      }
    }
<pre>
A link between a position in the original request input and a corresponding
time in the output audio. It's only supported via `&lt;mark&gt;` of SSML input.
</pre>

<code>repeated .google.cloud.texttospeech.v1beta1.Timepoint timepoints = 2;</code>
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/SynthesizeSpeechResponse.java