def METHOD_NAME(s, convert_eols=None):
    """Decode a raw base64 string.
    If convert_eols is set to a string value, all canonical email linefeeds,
    e.g. "\\r\\n", in the decoded text will be converted to the value of
    convert_eols.  os.linesep is a good choice for convert_eols if you are
    decoding a text attachment.
    This function does not parse a full MIME header value encoded with
    base64 (like =?iso-8859-1?b?bmloISBuaWgh?=) -- please use the high
    level email.header class for that functionality.
    """
    if not s:
        return s
    dec = a2b_base64(s)
    if convert_eols:
        return dec.replace(CRLF, convert_eols)
    return dec