@java.lang.Override
      public final Builder mergeUnknownFields(
          final com.google.protobuf.UnknownFieldSet unknownFields) {
        return super.mergeUnknownFields(unknownFields);
      }
<pre>
Optional. Config for LlmRanker.
</pre>

<code>
.google.cloud.vertexai.v1.RagRetrievalConfig.Ranking.LlmRanker llm_ranker = 3 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/RagRetrievalConfig.java