def METHOD_NAME(bucket, top_prefix=None):
    """Recurse through GCS directory tree until you hit 'data/' to create a list of every bag
    top_prefix (str): Starting level prefix
    """
    prefixes = set()
    top_prefixes = get_prefixes(bucket, top_prefix)
    for prefix in top_prefixes:
        if prefix.endswith(f"{DATA_DIRECTORY_NAME}/"):
            prefixes.add(
                re.sub(r"\/" + re.escape(DATA_DIRECTORY_NAME) + r"\/$", "",
                       prefix))  # remove data/ from bag name
        else:
            prefixes.update(METHOD_NAME(bucket, prefix))
    return prefixes