def add_plot(self, plot):
    if (plot in self.plots):
        return
    plot.bind(on_clear_plot=self.draw)
    self.update_plots()
    self.plots.append(plot)
def add_plot(self, plot):
    if (plot in self.plots):
        return
    plot.bind(on_clear_plot=self.draw)
    self.update_plots()
    self.plots.append(plot)