@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (((bitField0_ & 0x00000001) != 0)) {
      output.writeMessage(1, getStartTime());
    }
    if (((bitField0_ & 0x00000002) != 0)) {
      output.writeMessage(2, getLastUpdateTime());
    }
    if (java.lang.Double.doubleToRawLongBits(progressPercentage_) != 0) {
      output.writeDouble(3, progressPercentage_);
    }
    getUnknownFields().writeTo(output);
  }
<pre>
The progress of the most recent processing update in percentage, ie. 70.0%.
</pre>

<code>double progress_percentage = 3;</code>

@return The progressPercentage.
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/SynthesizeLongAudioMetadata.java