def METHOD_NAME(self):
    self.parent_widget.curveplot.clear_markings()
    for pair in self._range_widgets():
        for w in pair:
            if w.line not in self.parent_widget.curveplot.markings:
                w.line.report = self.parent_widget.curveplot
                self.parent_widget.curveplot.add_marking(w.line)