@java.lang.Override
    public final Builder mergeUnknownFields(
        final com.google.protobuf.UnknownFieldSet unknownFields) {
      return super.mergeUnknownFields(unknownFields);
    }
<pre>
Description of the content. Eg. "Recordings of federal supreme court
hearings from 2012".
</pre>

<code>string audio_topic = 10;</code>

@param value The bytes for audioTopic to set.
@return This builder for chaining.
java-speech/proto-google-cloud-speech-v1p1beta1/src/main/java/com/google/cloud/speech/v1p1beta1/RecognitionMetadata.java