public com.google.cloud.vertexai.api.RagRetrievalConfig.RankingOrBuilder getRankingOrBuilder() {
      if (rankingBuilder_ != null) {
        return rankingBuilder_.getMessageOrBuilder();
      } else {
        return ranking_ == null
            ? com.google.cloud.vertexai.api.RagRetrievalConfig.Ranking.getDefaultInstance()
            : ranking_;
      }
    }
<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