displayRegions and aspect ratio

Is there a method to set a new display region not scale what it renders when you resize the window, like the default display regions?

Learn from ShowBase.windowEvent :

                aspectRatio = self.getAspectRatio()
                if aspectRatio != self.__oldAspectRatio:
                    self.__oldAspectRatio = aspectRatio
                    # Fix up some anything that depends on the aspectRatio
                    self.camLens.setAspectRatio(aspectRatio)