private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.speech.v1.RecognitionMetadata,
            com.google.cloud.speech.v1.RecognitionMetadata.Builder,
            com.google.cloud.speech.v1.RecognitionMetadataOrBuilder>
        getMetadataFieldBuilder() {
      if (metadataBuilder_ == null) {
        metadataBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.speech.v1.RecognitionMetadata,
                com.google.cloud.speech.v1.RecognitionMetadata.Builder,
                com.google.cloud.speech.v1.RecognitionMetadataOrBuilder>(
                getMetadata(), getParentForChildren(), isClean());
        metadata_ = null;
      }
      return metadataBuilder_;
    }
<pre>
Metadata regarding this request.
</pre>

<code>.google.cloud.speech.v1.RecognitionMetadata metadata = 9;</code>
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/RecognitionConfig.java