code: def _polar(self):
          
          # This will be called inside LambertAxes.__init__ as well as every
          # time the axis is cleared, so we need the try/except to avoid having
          # multiple hidden axes when `cla` is _manually_ called.
          try:
              return self._hidden_polar_axes
          except AttributeError:
              fig = self.get_figure()
              self._hidden_polar_axes = fig.add_axes(self.get_position(True),
                                          frameon=False, projection='polar')
              self._hidden_polar_axes.format_coord = self._polar_format_coord
              return self._hidden_polar_axes
docs: The "hidden" polar axis used for azimuth labels.