I'd like to use the [Benchmark.js](https://www.npmjs.com/package/benchmark) module to test some asynchronous code written in node.js. Specifically, I want to fire ~10,000 requests to two servers (one written in node, one written in PHP), and track how long it takes for each server to complete all requests.

I was planning to write a simple node script to fire these requests using Benchmark, but I'm a little confused regarding how to use it with asynchronous code. Usually in node modules, there's some sort of a callback that you call when your async code is complete, or a Promise is returned from the function etc. But with Benchmark, from everything I'm reading in the docs, it doesn't seem to handle async at all.

Does anyone know what I should be doing or looking at? I can write the benchmark manually if need be; it just seems like a common enough use case that Benchmark or others would probably have already implemented it in their professional-grade testing libraries.

Thanks for any direction,
~ Nate