def _parse_name(wot_identifier):
    """
    Parse identifier of the forms: nick
                                   nick@key
                                   @key
    :Return: nick, key. If a part is not given return an empty string for it.
    
    >>> _parse_name("BabcomTest@123")
    ('BabcomTest', '123')
    """
    split = wot_identifier.split('@', 1)
    nickname_prefix = split[0]
    key_prefix = (split[1] if split[1:] else '')
    return nickname_prefix, key_prefix