unwind_segue.swift

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var contentView: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        contentView.backgroundColor = .yellow
    }
    
    // MARK: - Navigation
    @IBAction func unwind(segue: UIStoryboardSegue) {
        // Add this function
    }

}