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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 down(self, h, cr=True):
 """moves current vertical position h mm down cr True will navigate to the left margin """

        if cr:
            self.oPdf.ln(h=0)
        self.oPdf.set_y(self.oPdf.get_y() + h)