def METHOD_NAME(self):
    m_star = 10**10  # in M_sun
    rs = 0.01  # in Mpc
    # test bijective transformation
    sigma0, rs_angle = self.lensCosmo.hernquist_phys2angular(mass=m_star, rs=rs)
    m_star_new, rs_new = self.lensCosmo.hernquist_angular2phys(
        sigma0=sigma0, rs_angle=rs_angle
    )
    npt.assert_almost_equal(m_star_new, m_star, decimal=1)
    npt.assert_almost_equal(rs_new, rs, decimal=8)