How to use the rdtools.normalization.normalize_with_pvwatts function in rdtools

if system_size is None:
        renorm = True
        system_size = 1.0
    else:
        renorm = False

    pvwatts_kws = {
        "poa_global": poa,
        "P_ref": system_size,
        "T_cell": sensor_cell_temperature,
        "G_ref": g_ref,
        "T_ref": t_ref,
        "gamma_pdc": gamma_pdc
    }

    normalized, insolation = normalization.normalize_with_pvwatts(
        pv_energy, pvwatts_kws
    )

    if renorm:
        # Normalize to the 95th percentile for convenience;
        # this is renormalized out in the calculations but is relevant
        # to normalized_filter()
        x = normalized[np.isfinite(normalized)]
        normalized = normalized / x.quantile(0.95)
    return normalized, insolation