public com.google.cloud.speech.v1.CustomClass.Builder addCustomClassesBuilder(int index) {
      return getCustomClassesFieldBuilder()
          .addBuilder(index, com.google.cloud.speech.v1.CustomClass.getDefaultInstance());
    }
<pre>
The custom classes.
</pre>

<code>repeated .google.cloud.speech.v1.CustomClass custom_classes = 1;</code>
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/ListCustomClassesResponse.java