How to use the @xviz/io.XVIZEnvelope.Metadata function in @xviz/io

_getMetadata() {
    if (this.valid) {
      const xvizMetadataBuilder = new XVIZMetadataBuilder();
      this.bag.getMetadata(xvizMetadataBuilder, this.ros2xviz);

      const rawMetadata = xvizMetadataBuilder.getMetadata();
      this.metadata = XVIZEnvelope.Metadata(rawMetadata);
    }
  }

writeMetadata(xvizMetadata) {
    this._checkValid();
    this._saveTimestamp(xvizMetadata);

    if (this.options.envelope) {
      xvizMetadata = XVIZEnvelope.Metadata(xvizMetadata);
    }

    const msg = JSON.stringify(xvizMetadata);
    this.writeToSink('1-frame.json', msg);
  }

writeMetadata(xvizMetadata) {
    this._checkValid();
    this._saveTimestamp(xvizMetadata);

    if (this.options.envelope) {
      xvizMetadata = XVIZEnvelope.Metadata(xvizMetadata);
    }

    const glbFileBuffer = encodeBinaryXVIZ(xvizMetadata, this.encodingOptions);
    this.sink.writeSync(`1-frame.glb`, toBuffer(glbFileBuffer), {flag: 'w'});
  }

writeMetadata(xvizDirectory, xvizMetadata) {
    this._saveTimestamp(xvizMetadata);

    if (this.options.envelope) {
      xvizMetadata = XVIZEnvelope.Metadata(xvizMetadata);
    }

    if (this.options.binary) {
      const options = {
        flattenArrays: true
      };

      writeBinaryXVIZtoFile(this.sink, xvizDirectory, '1-frame', xvizMetadata, options);
    }

    if (this.options.json) {
      this.sink.writeSync(xvizDirectory, '1-frame.json', JSON.stringify(xvizMetadata));
    }
  }