         })
     }
     
-    private func visibilityCondition(button: NSButton, forLeft: Bool) -> Bool {
+    private func visibilityCondition(forButton button: NSButton, forLeftHandSide: Bool) -> Bool {
         let visibleRect = self.tabsView.visibleRect
-        if forLeft == true {
+        if forLeftHandSide == true {
             return NSMinX(button.frame) < NSMinX(visibleRect)
         }
         else {

    @objc private func scrollTabView(sender: AnyObject?) {
        let forLeft = (sender as? NSButton == self.scrollLeftButton)
            
        guard let tab = self.tabButtons().findFirst({ self.visibilityCondition($0, forLeft: forLeft) })
            else { return }

        NSAnimationContext.runAnimationGroup({ (context) in

        self.scrollLeftButton?.hidden = !showScrollButtons
        self.scrollRightButton?.hidden = !showScrollButtons
        if showScrollButtons == true {
            self.scrollLeftButton?.enabled = self.visibilityCondition(forButton: self.scrollLeftButton!, forLeftHandSide: true)
            self.scrollRightButton?.enabled = self.visibilityCondition(forButton: self.scrollRightButton!, forLeftHandSide: false)
        }
    }

