current position.  ``FollowedBy``
always returns a null token list. If any results names are defined
in the lookahead expression, those *will* be returned for access by
name.

Example::

    # use FollowedBy to match a label only if it is followed by a ':'
    data_word = Word(alphas)
    label = data_word + FollowedBy(':')
    attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))

    attr_expr[1, ...].parse_string("shape: SQUARE color: BLACK posn: upper left").pprint()

prints::

    [['shape', 'SQUARE'], ['color', 'BLACK'], ['posn', 'upper left']]
r�