How to use the tweakwcs.tpwcs.JWSTgWCS._check_tpcorr_structure function in tweakwcs

roll_ref = wcsinfo['roll_ref']

        self._wcsinfo = {'v2_ref': v2_ref, 'v3_ref': v3_ref,
                         'roll_ref': roll_ref}

        # perform additional check that if tangent plane correction is already
        # present in the WCS pipeline, it is of TPCorr class and that
        # its parameters are consistent with reference angles:
        frms = wcs.available_frames
        if 'v2v3corr' in frms:
            self._v23name = 'v2v3corr'
            self._tpcorr = deepcopy(
                wcs.pipeline[frms.index('v2v3corr') - 1][1]
            )
            self._default_tpcorr = None
            if not JWSTgWCS._check_tpcorr_structure(self._tpcorr):
                raise ValueError("Unsupported tangent-plance correction type.")

            # check that transformation parameters are consistent with
            # reference angles:
            v2ref, v3ref, roll = self._tpcorr['det_to_optic_axis'].angles.value

            eps_v2 = 10.0 * np.finfo(v2_ref).eps
            eps_v3 = 10.0 * np.finfo(v3_ref).eps
            eps_roll = 10.0 * np.finfo(roll_ref).eps
            if not (np.isclose(v2_ref, v2ref * 3600.0, rtol=eps_v2) and
                    np.isclose(v3_ref, -v3ref * 3600.0, rtol=eps_v3) and
                    np.isclose(roll_ref, roll, rtol=eps_roll)):
                raise ValueError(
                    "WCS/TPCorr parameters 'v2ref', 'v3ref', and/or 'roll' "
                    "differ from the corresponding reference values."
                )