def _round(self):
        """
        Subclasses may override this method.
        """
        for contour in self.contours:
            contour.round()
        for component in self.components:
            component.round()
        for anchor in self.anchors:
            anchor.round()
        for guideline in self.guidelines:
            guideline.round()
        self.width = normalizers.normalizeRounding(self.width)
        self.height = normalizers.normalizeRounding(self.height)
Subclasses may override this method.