def METHOD_NAME(self):
    logger = logging.getLogger('simsopt.field.tracing')
    logger.setLevel(1)
    # Test a toroidal magnetic field with no rotational transform
    R0test = 1.3
    B0test = 0.8
    Bfield = ToroidalField(R0test, B0test)
    nlines = 10
    R0 = [1.1 + i*0.1 for i in range(nlines)]
    Z0 = [0 for i in range(nlines)]
    nphis = 10
    phis = np.linspace(0, 2*np.pi, nphis, endpoint=False)
    res_tys, res_phi_hits = compute_fieldlines(
        Bfield, R0, Z0, tmax=100, phis=phis, stopping_criteria=[])
    for i in range(nlines):
        assert np.allclose(res_tys[i][:, 3], 0.)
        assert np.allclose(np.linalg.norm(res_tys[i][:, 1:3], axis=1), R0[i])
        assert validate_phi_hits(res_phi_hits[i], nphis)
    if with_evtk:
        particles_to_vtk(res_tys, '/tmp/fieldlines')