@java.lang.Override
  public int getSerializedSize() {
    int size = memoizedSize;
    if (size != -1) return size;

    size = 0;
    if (inputSourceCase_ == 1) {
      size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, inputSource_);
    }
    if (inputSourceCase_ == 5) {
      size += com.google.protobuf.GeneratedMessageV3.computeStringSize(5, inputSource_);
    }
    size += getUnknownFields().getSerializedSize();
    memoizedSize = size;
    return size;
  }
<pre>
Markup for HD voices specifically. This field may not be used with any
other voices.
</pre>

<code>string markup = 5;</code>

@return The bytes for markup.
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/StreamingSynthesisInput.java