They meant something like "var n = Date.now". However, there is no guarantee that this will work since it assumes that `this` isn't used by that function. E.g

They meant something like "var n = Date.now". However, there is no guarantee that this will work since it assumes that `this` isn't used by that function. E.g. if you want to do something like that with console.log or document.querySelector, you have to use bind: var log = console.log.bind(console); var qs = document.querySelector.bind(document);