@java.lang.Override
    public Builder clear() {
      super.clear();
      bitField0_ = 0;
      if (vertexAiSearchBuilder_ != null) {
        vertexAiSearchBuilder_.clear();
      }
      if (vertexRagStoreBuilder_ != null) {
        vertexRagStoreBuilder_.clear();
      }
      disableAttribution_ = false;
      sourceCase_ = 0;
      source_ = null;
      return this;
    }
<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