private void buildPartialOneofs(com.google.cloud.vertexai.api.Retrieval result) {
      result.sourceCase_ = sourceCase_;
      result.source_ = this.source_;
      if (sourceCase_ == 2 && vertexAiSearchBuilder_ != null) {
        result.source_ = vertexAiSearchBuilder_.build();
      }
      if (sourceCase_ == 4 && vertexRagStoreBuilder_ != null) {
        result.source_ = vertexRagStoreBuilder_.build();
      }
    }
<pre>
Defines a retrieval tool that model can call to access external knowledge.
</pre>

Protobuf type {@code google.cloud.vertexai.v1.Retrieval}
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Retrieval.java