private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.video.stitcher.v1.IframeAdResource,
            com.google.cloud.video.stitcher.v1.IframeAdResource.Builder,
            com.google.cloud.video.stitcher.v1.IframeAdResourceOrBuilder>
        getIframeAdResourceFieldBuilder() {
      if (iframeAdResourceBuilder_ == null) {
        if (!(adResourceCase_ == 10)) {
          adResource_ = com.google.cloud.video.stitcher.v1.IframeAdResource.getDefaultInstance();
        }
        iframeAdResourceBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.video.stitcher.v1.IframeAdResource,
                com.google.cloud.video.stitcher.v1.IframeAdResource.Builder,
                com.google.cloud.video.stitcher.v1.IframeAdResourceOrBuilder>(
                (com.google.cloud.video.stitcher.v1.IframeAdResource) adResource_,
                getParentForChildren(),
                isClean());
        adResource_ = null;
      }
      adResourceCase_ = 10;
      onChanged();
      return iframeAdResourceBuilder_;
    }
<pre>
The IFrame ad resource associated with the companion ad.
</pre>

<code>.google.cloud.video.stitcher.v1.IframeAdResource iframe_ad_resource = 10;</code>
java-video-stitcher/proto-google-cloud-video-stitcher-v1/src/main/java/com/google/cloud/video/stitcher/v1/Companion.java