This is part of the [watch-dom module](https://github.com/turn/watch-dom), and is concatenated with angular-sticky-table-header as part of the build process. watch-dom has a similar API to angular $watches, so calling the function returned by the $watch should disable the $watch. The `bind` allows the consumer to call the returned function without explicitly setting a receiver for the call (meaning, you could call `fn()` instead of `thing.fn()`).