private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfig,
            com.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfig.Builder,
            com.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfigOrBuilder>
        getObjectTrackingConfigFieldBuilder() {
      if (objectTrackingConfigBuilder_ == null) {
        objectTrackingConfigBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfig,
                com.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfig.Builder,
                com.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfigOrBuilder>(
                getObjectTrackingConfig(), getParentForChildren(), isClean());
        objectTrackingConfig_ = null;
      }
      return objectTrackingConfigBuilder_;
    }
<pre>
Config for OBJECT_TRACKING.
</pre>

<code>
.google.cloud.videointelligence.v1p3beta1.ObjectTrackingConfig object_tracking_config = 13;
</code>
java-video-intelligence/proto-google-cloud-video-intelligence-v1p3beta1/src/main/java/com/google/cloud/videointelligence/v1p3beta1/VideoContext.java