public com.google.cloud.videointelligence.v1.NormalizedBoundingBoxOrBuilder
        getNormalizedBoundingBoxesOrBuilder(int index) {
      if (normalizedBoundingBoxesBuilder_ == null) {
        return normalizedBoundingBoxes_.get(index);
      } else {
        return normalizedBoundingBoxesBuilder_.getMessageOrBuilder(index);
      }
    }
<pre>
Normalized Bounding boxes in a frame.
There can be more than one boxes if the same face is detected in multiple
locations within the current frame.
</pre>

<code>
repeated .google.cloud.videointelligence.v1.NormalizedBoundingBox normalized_bounding_boxes = 1;
</code>
java-video-intelligence/proto-google-cloud-video-intelligence-v1/src/main/java/com/google/cloud/videointelligence/v1/FaceFrame.java