```javascript //FROM function circum(radius) {...} //TO function circumference(radius) {...} ``` If deprecating something like API code a useful way of accomplishing that easily might be to do something like this: ```javascript //FROM function circum(radius) { return Math.PI * 2 * radius; } //TO function circum(radius) { console.log("This function is deprecated, please use circumference()"); return circumference(radius); } function circumference(radius) { return Math.PI * 2 * radius; } ``` This also makes it easy to refactor in place and only change small things like what the contents are of `circum()` this way if it breaks code we can just handle it in our new function body and all references to `circum()` are intact until we're able to migrate everything to the new function declaration.