- (NSString *) title;
- (NSString *) backButtonTitle;
-- (NSString *) rightButtonTitle;
+- (id) rightButtonTitle;
- (NSString *) leftButtonTitle;
- (UIView *) accessoryView;
+- (UIImage *) rightButtonImage;
+
- (UINavigationButtonStyle) leftButtonStyle;
- (UINavigationButtonStyle) rightButtonStyle;