public com.google.cloud.speech.v1p1beta1.SpeechAdaptation.ABNFGrammar getAbnfGrammar() {
      if (abnfGrammarBuilder_ == null) {
        return abnfGrammar_ == null
            ? com.google.cloud.speech.v1p1beta1.SpeechAdaptation.ABNFGrammar.getDefaultInstance()
            : abnfGrammar_;
      } else {
        return abnfGrammarBuilder_.getMessage();
      }
    }
<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.v1p1beta1.SpeechAdaptation.ABNFGrammar abnf_grammar = 4;</code>

@return The abnfGrammar.
java-speech/proto-google-cloud-speech-v1p1beta1/src/main/java/com/google/cloud/speech/v1p1beta1/SpeechAdaptation.java