@objc
public protocol HeroViewControllerDelegate

                heroWillStartAnimatingFrom(viewController:)
                `

@objc
optional func heroWillStartAnimatingFrom(viewController: UIViewController)

                heroDidEndAnimatingFrom(viewController:)
                `

@objc
optional func heroDidEndAnimatingFrom(viewController: UIViewController)

                heroDidCancelAnimatingFrom(viewController:)
                `

@objc
optional func heroDidCancelAnimatingFrom(viewController: UIViewController)

                heroWillStartTransition()
                `

@objc
optional func heroWillStartTransition()

                heroDidEndTransition()
                `

@objc
optional func heroDidEndTransition()

                heroDidCancelTransition()
                `

@objc
optional func heroDidCancelTransition()

                heroWillStartAnimatingTo(viewController:)
                `

@objc
optional func heroWillStartAnimatingTo(viewController: UIViewController)

                heroDidEndAnimatingTo(viewController:)
                `

@objc
optional func heroDidEndAnimatingTo(viewController: UIViewController)

                heroDidCancelAnimatingTo(viewController:)
                `

@objc
optional func heroDidCancelAnimatingTo(viewController: UIViewController)