public Builder clearCitationMetadata() {
      bitField0_ = (bitField0_ & ~0x00000100);
      citationMetadata_ = null;
      if (citationMetadataBuilder_ != null) {
        citationMetadataBuilder_.dispose();
        citationMetadataBuilder_ = null;
      }
      onChanged();
      return this;
    }
<pre>
Output only. Source attribution of the generated content.
</pre>

<code>
.google.cloud.vertexai.v1.CitationMetadata citation_metadata = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Candidate.java