@java.lang.Override
  public com.google.cloud.speech.v2.SpeechAdaptation getDefaultInstanceForType() {
    return DEFAULT_INSTANCE;
  }
<pre>
A list of inline CustomClasses. Existing CustomClass resources can be
referenced directly in a PhraseSet.
</pre>

<code>repeated .google.cloud.speech.v2.CustomClass custom_classes = 2;</code>
java-speech/proto-google-cloud-speech-v2/src/main/java/com/google/cloud/speech/v2/SpeechAdaptation.java