public Builder mergeGenerationConfig(com.google.cloud.vertexai.api.GenerationConfig value) {
      if (generationConfigBuilder_ == null) {
        if (((bitField0_ & 0x00000040) != 0)
            && generationConfig_ != null
            && generationConfig_
                != com.google.cloud.vertexai.api.GenerationConfig.getDefaultInstance()) {
          getGenerationConfigBuilder().mergeFrom(value);
        } else {
          generationConfig_ = value;
        }
      } else {
        generationConfigBuilder_.mergeFrom(value);
      }
      if (generationConfig_ != null) {
        bitField0_ |= 0x00000040;
        onChanged();
      }
      return this;
    }
<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