def METHOD_NAME(rng):
    """Get an SED for this galaxy at a random redshift"""
    z = rng() * 4  # uniform from 0 to 4.
    index = int(rng() * len(sed_list))
    # This means there is a new sed object each time, but the disk I/O is amortized.
    sed = sed_list[index].atRedshift(z)
    return sed