def METHOD_NAME(full_cov, wb):
    dwb = WidebandDownhillFitter(wb.toas, wb.model_init)
    with contextlib.suppress(MaxiterReached):
        dwb.fit_toas(maxiter=1, full_cov=full_cov)
    assert abs(wb.resids.chi2 - dwb.resids.chi2) < 0.01