I'm just trying to perform a very simple system API call, setting a UITableView to **editing.**

However I have no idea what the compiler is complaining about:

```
let isEditing = self.tableView?.editing
self.tableView?.setEditing(!isEditing, animated: true)

```

Error Message: 

> 
> Optional type '\_' cannot be used as a boolean; test for '!= nil' instead
> 
> 
> 

Thankful for any advice!