 
 }
 
-extension SMMMonitorWindowController {
+extension SMMMonitorWindowController: NSUserInterfaceValidations {
 
     // MARK: General UI
 


import Cocoa

class SMMMonitorWindowController: NSWindowController, NSUserInterfaceValidations {

    @objc init() {
        super.init(window: nil)

        // Then expand the outline view to show this source, and scroll it to be visible.
        guard groupedInputSources != nil else { return }
        for group in groupedInputSources! {
            if let itemDict = group as? [String:Any] {
                let itemNotExpandableNumber = itemDict["isNotExpandable"] as? NSNumber
                let notExpandable = (itemNotExpandableNumber?.boolValue) ?? false
                if !notExpandable {
                    let groupSources = itemDict["sources"] as! [SMInputStreamSource]
                    for source in groupSources {
                        if sources.contains(source) {
                            // Found one!
                            sourcesOutlineView.expandItem(group)
                            sourcesOutlineView.scrollRowToVisible(sourcesOutlineView.row(forItem: source))

                            // And now we're done
                            break
                        }
                    }
                }
            }
