// init
let root = AKBaseViewController()
let nav = AKNavigationController(rootViewController: root)

// set navTitle
root.navTitle = "Hello"

// set navTitle color
root.navTitleColor = .green

// set navBar Color
root.navBarBackgroundColor = .orange

// set navBar backgroundImage
root.navBarBackgroundImage = UIImage(named: "xxx")

// set single button
root.rightImage = UIImage(named: "ak_back")
  // or
root.rightTitle = "right title"

// set button color
root.rightButtonColor = .red

// set a group of buttons 
root.leftItems = [
    AKNavigationItem(UIImage(named: "ak_back"), action:{[unowned self] in
        self.log("l1 clicked")
    }),
    AKNavigationItem("l2", action: {[unowned self] in
        self.log("l2 clicked")
    })
]

// change statusBar
root.statusBarStyle = .light // .dark

// hide navBar
root.hideNavBar = true