@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (((bitField0_ & 0x00000001) != 0)) {
      output.writeMessage(1, getLatLng());
    }
    if (((bitField0_ & 0x00000002) != 0)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 2, languageCode_);
    }
    getUnknownFields().writeTo(output);
  }
<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