def do_flipper(parser, token):
    """The flipper tag takes two arguments: the user to look up and the feature
    to compare against.
    """
    nodelist = parser.parse(('endflipper',))
    tag_name, user_key, feature = token.split_contents()
    parser.delete_first_token()
    return FlipperNode(nodelist, user_key, feature)