private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.video.stitcher.v1.HtmlAdResource,
            com.google.cloud.video.stitcher.v1.HtmlAdResource.Builder,
            com.google.cloud.video.stitcher.v1.HtmlAdResourceOrBuilder>
        getHtmlAdResourceFieldBuilder() {
      if (htmlAdResourceBuilder_ == null) {
        if (!(adResourceCase_ == 12)) {
          adResource_ = com.google.cloud.video.stitcher.v1.HtmlAdResource.getDefaultInstance();
        }
        htmlAdResourceBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.video.stitcher.v1.HtmlAdResource,
                com.google.cloud.video.stitcher.v1.HtmlAdResource.Builder,
                com.google.cloud.video.stitcher.v1.HtmlAdResourceOrBuilder>(
                (com.google.cloud.video.stitcher.v1.HtmlAdResource) adResource_,
                getParentForChildren(),
                isClean());
        adResource_ = null;
      }
      adResourceCase_ = 12;
      onChanged();
      return htmlAdResourceBuilder_;
    }
<pre>
The HTML ad resource associated with the companion ad.
</pre>

<code>.google.cloud.video.stitcher.v1.HtmlAdResource html_ad_resource = 12;</code>
java-video-stitcher/proto-google-cloud-video-stitcher-v1/src/main/java/com/google/cloud/video/stitcher/v1/Companion.java