private void ensureAbnfStringsIsMutable() {
        if (!abnfStrings_.isModifiable()) {
          abnfStrings_ = new com.google.protobuf.LazyStringArrayList(abnfStrings_);
        }
        bitField0_ |= 0x00000001;
      }
Protobuf type {@code google.cloud.speech.v1.SpeechAdaptation.ABNFGrammar}
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/SpeechAdaptation.java