private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.speech.v1.SpeechAdaptation,
            com.google.cloud.speech.v1.SpeechAdaptation.Builder,
            com.google.cloud.speech.v1.SpeechAdaptationOrBuilder>
        getAdaptationFieldBuilder() {
      if (adaptationBuilder_ == null) {
        adaptationBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.speech.v1.SpeechAdaptation,
                com.google.cloud.speech.v1.SpeechAdaptation.Builder,
                com.google.cloud.speech.v1.SpeechAdaptationOrBuilder>(
                getAdaptation(), getParentForChildren(), isClean());
        adaptation_ = null;
      }
      return adaptationBuilder_;
    }
<pre>
Speech adaptation configuration improves the accuracy of speech
recognition. For more information, see the [speech
adaptation](https://cloud.google.com/speech-to-text/docs/adaptation)
documentation.
When speech adaptation is set it supersedes the `speech_contexts` field.
</pre>

<code>.google.cloud.speech.v1.SpeechAdaptation adaptation = 20;</code>
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/RecognitionConfig.java