Wrapping up boilerplate code - Interface builder

UIViewControllerInitFromStoryboard.swift

import UIKit

extension UIViewController {
    // must override to provide storyboard
    @objc class var fromStoryboard: UIStoryboard? { return nil }
    
    // optional override to provide storyboardId
    @objc class var storyboardId: String { return String(describing: self) }
    
    static func instantiate() -> Self {
        let id = storyboardId
        if let fromStoryboard = fromStoryboard {
            let viewController = fromStoryboard.instantiateViewController(withIdentifier: id)
            if let casted = viewController as? Self {
                return casted
            } else {
                assertionFailure("cannot cast to \(String(describing: self))")
            }
        } else {
            assertionFailure("fromStoryboard is not defined for \(String(describing: self))")
        }
        return Self() // wont come here
    }
}