docs: def set_scalebar(self, location='lower right'):
          """Show marker area scale.
  
          :param location: the location of the label inside the plot.  May
              be one of 'center', 'upper right', 'lower right', 'upper
              left', 'lower left'.
  
          """
          if location in RELATIVE_NODE_LOCATIONS:
              scalebar = RELATIVE_NODE_LOCATIONS[location].copy()
              self.scalebar = scalebar
          else:
              raise RuntimeError('Unknown scalebar location: %s' % location)