private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.vertexai.api.GenerationConfig,
            com.google.cloud.vertexai.api.GenerationConfig.Builder,
            com.google.cloud.vertexai.api.GenerationConfigOrBuilder>
        getGenerationConfigFieldBuilder() {
      if (generationConfigBuilder_ == null) {
        generationConfigBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.vertexai.api.GenerationConfig,
                com.google.cloud.vertexai.api.GenerationConfig.Builder,
                com.google.cloud.vertexai.api.GenerationConfigOrBuilder>(
                getGenerationConfig(), getParentForChildren(), isClean());
        generationConfig_ = null;
      }
      return generationConfigBuilder_;
    }
<pre>
Optional. Generation config that the model will use to generate the
response.
</pre>

<code>
optional .google.cloud.vertexai.v1.GenerationConfig generation_config = 7 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/CountTokensRequest.java