@java.lang.Override
  @SuppressWarnings({"unused"})
  protected java.lang.Object newInstance(UnusedPrivateParameter unused) {
    return new Retrieval();
  }
<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