public Builder setRanking(
        com.google.cloud.vertexai.api.RagRetrievalConfig.Ranking.Builder builderForValue) {
      if (rankingBuilder_ == null) {
        ranking_ = builderForValue.build();
      } else {
        rankingBuilder_.setMessage(builderForValue.build());
      }
      bitField0_ |= 0x00000004;
      onChanged();
      return this;
    }
<pre>
Optional. Config for ranking and reranking.
</pre>

<code>
.google.cloud.vertexai.v1.RagRetrievalConfig.Ranking ranking = 4 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/RagRetrievalConfig.java