@waitFor label

```javascript
@waitFor('my-label')
async doSomething() {}
```

Errors with

```
wait-for.js:38 Uncaught (in promise) TypeError: fn.call is not a function
at wait-for.js:38
at index.js:15
at Array.reduce ()
at _applyDecoratedDescriptor (index.js:15)
at Module.callback (index.js:122)
at Module.exports (loader.js:106)
at requireModule (loader.js:27)
at Class._extractDefaultExport (index.js:463)
at Class.resolveOther (index.js:123)
at Class.resolve (index.js:186)
```