function send(res, bufferOrString) {
  // Pseudo API and Express API and Koa API
  if (typeof res.send === "function") {
    res.send(bufferOrString);
    return;
  }

  res.end(bufferOrString);
}
@template {ServerResponse & ExpectedServerResponse} Response
@param {Response} res res
@param {string | Buffer} bufferOrString buffer or string
@returns {void}