Callback to promise with adapter - easiest way to convert a function that relies on a callback that is not the last argument

CallbackToPromiseWithAdapter.js

const util = require('util');	

postRequest(url, postData, cb, authToken, retries, inOptions) { (...) }

postRequestAsync(url, postData, authToken, retries, inOptions) {
  const adapter = (url, postData, authToken, retries, inOptions, cb) => {
    this.postRequest(url, postData, cb, authToken, retries, inOptions);
  };
  return util.promisify(adapter)(url, postData, authToken, retries, inOptions);
}