<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def plot(self, axis, title=None, saved=False):
 """ Plots the planar average electrostatic potential against the Long range and short range models from Freysoldt """


        x = self.metadata['pot_plot_data'][axis]['x']
        v_R = self.metadata['pot_plot_data'][axis]['Vr']
        dft_diff = self.metadata['pot_plot_data'][axis]['dft_diff']
        final_shift = self.metadata['pot_plot_data'][axis]['final_shift']
        check = self.metadata['pot_plot_data'][axis]['check']

        plt.figure()
        plt.clf()
        plt.plot(x, v_R, c="green", zorder=1, label="long range from model")
        plt.plot(x, dft_diff, c="red", label="DFT locpot diff")
        plt.plot(x, final_shift, c="blue", label="short range (aligned)")

        tmpx = [x[i] for i in range(check[0], check[1])]
        plt.fill_between(tmpx, -100, 100, facecolor="red", alpha=0.15, label="sampling region")

        plt.xlim(round(x[0]), round(x[-1]))
        ymin = min(min(v_R), min(dft_diff), min(final_shift))
        ymax = max(max(v_R), max(dft_diff), max(final_shift))
        plt.ylim(-0.2 + ymin, 0.2 + ymax)
        plt.xlabel("distance along axis ($\AA$)", fontsize=15)
        plt.ylabel("Potential (V)", fontsize=15)
        plt.legend(loc=9)
        plt.axhline(y=0, linewidth=0.2, color="black")
        plt.title(str(title) + " defect potential", fontsize=18)
        plt.xlim(0, max(x))
        if saved:
            plt.savefig(str(title) + "FreyplnravgPlot.pdf")
        else:
            return plt