public Builder addFacetResults(com.google.cloud.visionai.v1.FacetGroup value) {
      if (facetResultsBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        ensureFacetResultsIsMutable();
        facetResults_.add(value);
        onChanged();
      } else {
        facetResultsBuilder_.addMessage(value);
      }
      return this;
    }
<pre>
Facet search results of a given query, which contains user's
already-selected facet values and updated facet search results.
</pre>

<code>repeated .google.cloud.visionai.v1.FacetGroup facet_results = 3;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/SearchAssetsResponse.java