Open Sensor menu on top of existing frame

def on_graphs_menu_open(self, widget):
        """Open Sensor menu on top of existing frame"""
        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])