public Builder clearRagResources() {
      if (ragResourcesBuilder_ == null) {
        ragResources_ = java.util.Collections.emptyList();
        bitField0_ = (bitField0_ & ~0x00000001);
        onChanged();
      } else {
        ragResourcesBuilder_.clear();
      }
      return this;
    }
<pre>
Optional. The representation of the rag source. It can be used to specify
corpus only or ragfiles. Currently only support one corpus or multiple
files from one corpus. In the future we may open up multiple corpora
support.
</pre>

<code>
repeated .google.cloud.vertexai.v1.VertexRagStore.RagResource rag_resources = 4 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/VertexRagStore.java