New patterns enabled by async functions. The more I live with async/await the more I discover new patterns and leave behind many old ones. One constraint of working with async/await is that we only have a single return value from async functions. In the old callback world, you could pass more than one success object to the callback. In addition to multiple callback results, you also had the option
![Constraint based APIs for async/await](https://cdn-ak-scissors.b.st-hatena.com/image/square/85d8555089f7c74ce829ec5adaeba56ca15ee3a3/height=288;version=1;width=512/https%3A%2F%2Fmiro.medium.com%2Fv2%2Fresize%3Afit%3A850%2F1%2AIoh7PPcMQ2EQCg7S44sHxg.jpeg)