docs: 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)