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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _update_clipper(self):
 """Called whenever the clipper for this widget may need to be updated. """

        if self.clip_children and self._clipper is None:
            self._clipper = Clipper()
        elif not self.clip_children:
            self._clipper = None

        if self._clipper is None:
            return
        self._clipper.rect = self.inner_rect
        self._clipper.transform = self.get_transform('framebuffer', 'visual')