def remove_cv(self, index):
        """ Attempts to remove the cv at the given index, does nothing if only
        one control point is left """
        if len(self._cv_points) > 1:
            del self._cv_points[index]
        self._modified = True
        self.build_curve()
 Attempts to remove the cv at the given index, does nothing if only
        one control point is left 
metadrive/render_pipeline/rpcore/util/smooth_connected_curve.py