@java.lang.Override
  public com.google.protobuf.ByteString getLanguageCodeBytes() {
    java.lang.Object ref = languageCode_;
    if (ref instanceof java.lang.String) {
      com.google.protobuf.ByteString b =
          com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
      languageCode_ = b;
      return b;
    } else {
      return (com.google.protobuf.ByteString) ref;
    }
  }
<pre>
The language code of the user.
</pre>

<code>optional string language_code = 2;</code>

@return The bytes for languageCode.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/RetrievalConfig.java