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