code: def einstein_radius_in_units(self, unit_length='arcsec', kpc_per_arcsec=None):
          
  
          if self.has_mass_profile:
              return sum(map(lambda p: p.einstein_radius_in_units(unit_length=unit_length, kpc_per_arcsec=kpc_per_arcsec),
                             self.mass_profiles))
          else:
              return None
docs: The Einstein Radius of this galaxy, which is the sum of Einstein Radii of its mass profiles.
  
          If the galaxy is composed of multiple ellipitcal profiles with different axis-ratios, this Einstein Radius \
          may be inaccurate. This is because the differently oriented ellipses of each mass profile