How to use the autogalaxy.util.cosmology_util function in autogalaxy

def critical_surface_density_between_planes_in_units(
        self, i, j, unit_length="arcsec", unit_mass="solMass"
    ):
        return cosmology_util.critical_surface_density_between_redshifts_from(
            redshift_0=self.plane_redshifts[i],
            redshift_1=self.plane_redshifts[j],
            cosmology=self.cosmology,
            unit_length=unit_length,
            unit_mass=unit_mass,
        )

def angular_diameter_distance_between_planes_in_units(
        self, i, j, unit_length="arcsec"
    ):
        return cosmology_util.angular_diameter_distance_between_redshifts_from(
            redshift_0=self.plane_redshifts[i],
            redshift_1=self.plane_redshifts[j],
            cosmology=self.cosmology,
            unit_length=unit_length,
        )