Promises

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise

Imagine you had an object for abstract plans. You would need: - The plan contents (ie a function body) - A "mark as successful" method - A "mark as failed" method

To combine individual plans into multi-step processes, you would also want to be able to assign: - "Next step" (ie what to do on success) - "Backup plan" (ie what to do on failure)