@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (chunkTypeCase_ == 1) {
      output.writeMessage(1, (com.google.cloud.vertexai.api.GroundingChunk.Web) chunkType_);
    }
    if (chunkTypeCase_ == 2) {
      output.writeMessage(
          2, (com.google.cloud.vertexai.api.GroundingChunk.RetrievedContext) chunkType_);
    }
    getUnknownFields().writeTo(output);
  }
<pre>
Grounding chunk from context retrieved by the retrieval tools.
</pre>

<code>.google.cloud.vertexai.v1.GroundingChunk.RetrievedContext retrieved_context = 2;</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/GroundingChunk.java