@java.lang.Override
    public final Builder mergeUnknownFields(
        final com.google.protobuf.UnknownFieldSet unknownFields) {
      return super.mergeUnknownFields(unknownFields);
    }
<pre>
Augmented Backus-Naur form (ABNF) is a standardized grammar notation
comprised by a set of derivation rules.
See specifications: https://www.w3.org/TR/speech-grammar
</pre>

<code>.google.cloud.speech.v1.SpeechAdaptation.ABNFGrammar abnf_grammar = 4;</code>
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/SpeechAdaptation.java