code: def autoLayout(self, size=None):
          
          if size is None:
              size = self._view.size()
          
          self.setSceneRect(0, 0, size.width(), size.height())
          for item in self.items():
              if isinstance(item, XWalkthroughGraphic):
                  item.autoLayout(size)
docs: Updates the layout for the graphics within this scene.