<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _extra_regression_kwargs(self):
 """ List of additional kwargs to use in regression tests. """


        # larger than default sometimes needed when extrapolating
        omega_switch_test = 0.019

        extra_args = []
        extra_args.append({
            'omega0': 5e-3,
            'PN_approximant': 'SpinTaylorT4',
            'PN_dt': 0.1,
            'PN_spin_order': 7,
            'PN_phase_order': 7,
            'omega_switch': omega_switch_test,
            })


        extra_args.append({
            'omega0': 6e-3,
            'PN_approximant': 'SpinTaylorT1',
            'PN_dt': 0.5,
            'PN_spin_order': 5,
            'PN_phase_order': 7,
            'omega_switch': omega_switch_test,
            })

        extra_args.append({
            'omega0': 7e-3,
            'PN_approximant': 'SpinTaylorT2',
            'PN_dt': 1,
            'PN_spin_order': 7,
            'PN_phase_order': 5,
            'omega_switch': omega_switch_test,
            })

        # These should be pure NRSur7dq2
        extra_args.append({'omega0': 3e-2})
        extra_args.append({'omega0': 5e-2})

        return extra_args