src/statics/asCallback.js
function asCallback(promise, cb) {
  promise.then((res) => cb(null, res), cb);
}
function asCallback(promise, cb) {
  promise.then((res) => cb(null, res), cb);
}
Calls the specified callback with the result of the promise.

Note that if the callback throws a synchronous error, then we will trigger an unhandled
rejection.

@param {Promise} promise
@param {Function<Err, Any>} cb - An errback.