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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 _add_scale(self, m, ax1):
        ''' Add scale to the map instance '''

        lol, loM, lam, laM = self.lambert_window(
            0.6 * self.size_window, self.lat0, self.lon0)
        m.drawmapscale(loM, lam, self.lon0, self.lat0, 10,
                       barstyle='fancy', units='km',
                       fontsize=24, yoffset=None,
                       labelstyle='simple',
                       fontcolor='k',
                       fillcolor1='w',
                       fillcolor2='k', ax=ax1,
                       format='%d',
                       zorder=2)