Reusable.swift

public protocol StoryboardBased: class {
  static var storyboard: UIStoryboard { get }
}

public extension StoryboardBased {
  static var storyboard: UIStoryboard {
    return UIStoryboard(name: String(describing: self), bundle: Bundle(for: self))
  }
}

public extension StoryboardBased where Self: UIViewController {
  static func instantiate() -> Self {
    guard let vc = storyboard.instantiateInitialViewController() as? Self else {
      fatalError("The VC of \(sceneStoryboard) is not of class \(self)")
    }
    return vc
  }
}