       - parameter duration: The time duration toast will displayed on the screen
       - parameter position: The position that toast will displayed
      */
-    public func showToast(toastView: UIView!,
+    public func showToast(toastView: UIView,
                           fadeIn: TimeInterval = Constants.ToastFadeDuration,
                           duration: TimeInterval!,
                           position: ToastPosition) {

                          titleColor: UIColor?,
                          messageColor: UIColor?,
                          font: UIFont?) {
        let toastView = self.toastView(message: message,
                                       title: title,
                                       image: nil,
                                       backgroundColor: backgroundColor,
                                       titleColor: titleColor,
                                       messageColor: messageColor,
                                       font: font)
        self.showToast(toastView: toastView,
                       fadeIn: fadeIn,
                       duration: duration,

                          titleColor: UIColor?,
                          messageColor: UIColor?,
                          font: UIFont?) {
        guard let toastView = self.toastView(message: message,
                                             title: title,
                                             image: nil,
                                             backgroundColor: backgroundColor,
                                             titleColor: titleColor,
                                             messageColor: messageColor,
                                             font: font) else {
                                        return
        }
        self.showToast(toastView: toastView,
                       duration: Constants.ToastDuration,
                       position: .bottom)
