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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def __init_vertical_plot(self):
 """ set up the vertical profile plot Returns ------- """

        # clear the plot if lines have already been drawn on it
        if len(self.ax2.lines) > 0:
            self.ax2.cla()
        # set up the vertical profile plot
        self.ax2.set_ylabel(self.datalabel, fontsize=self.fontsize)
        self.ax2.set_xlabel(self.spectrumlabel, fontsize=self.fontsize)
        self.ax2.set_title('vertical point profiles', fontsize=self.fontsize)
        self.ax2.set_xlim([1, self.bands])
        # plot vertical line at the slider position
        self.vline = self.ax2.axvline(self.slider.value, color='black')