code: def on_graphs_menu_open(self, widget):
          
          self.original_widget = urwid.Overlay(
              self.graphs_menu.main_window,
              self.original_widget,
              ('relative', self.left_margin),
              self.graphs_menu.get_size()[1],
              ('relative', self.top_margin),
              self.graphs_menu.get_size()[0])
docs: Open Sensor menu on top of existing frame