code: async function convertStream(data, streaming) {
    if (!streaming && util.isStream(data)) {
      return stream.readToEnd(data);
    }
    if (streaming && !util.isStream(data)) {
      data = new ReadableStream({
        start(controller) {
          controller.enqueue(data);
          controller.close();
        }
      });
    }
    if (streaming === 'node') {
      data = stream.webToNode(data);
    }
    return data;
  }
docs: Convert data to or from Stream
  @param  {Object} data                   the data to convert
  @param  {'web'|'node'|false} streaming  (optional) whether to return a ReadableStream
  @returns {Object}                       the data in the respective format