def _onRemoved(self, mobject, modifier, _=None):
    self._removed = True
    for callback in self.onRemoved:
        try:
            callback()
        except Exception:
            traceback.print_exc()
def _onRemoved(self, mobject, modifier, _=None):
    self._removed = True
    for callback in self.onRemoved:
        try:
            callback()
        except Exception:
            traceback.print_exc()