def METHOD_NAME(self):
    model = self.model.copy()
    t0 = model.parameters
    _, res1 = fit_powerspectrum(self.ps, model)
    _, res2 = fit_powerspectrum(self.ps, model, t0)
    _, res3 = fit_crossspectrum(self.ps, model, t0, priors=self.priors)
    assert np.all(np.isclose(t0, res1.p_opt, rtol=0.5, atol=0.5))
    assert np.all(np.isclose(t0, res2.p_opt, rtol=0.5, atol=0.5))
    assert np.all(np.isclose(t0, res3.p_opt, rtol=0.5, atol=0.5))