taby_display.swift

func displayCurrentTab(_ tabIndex: Int){
        if let vc = viewControllerForSelectedSegmentIndex(tabIndex) {
            
            self.addChildViewController(vc)
            vc.didMove(toParentViewController: self)
            
            vc.view.frame = self.contentView.bounds
            self.contentView.addSubview(vc.view)
            self.currentViewController = vc
        }
    }