'widen range of tokens to get punctuation to the left of
start and to the right of stop'

def _widen(self, start, stop):

    if (start < len(self.tokens)):
        while ((start > 0) and RE_PUNCTUATION.match(self.tokens[(start - 1)])):
            start -= 1
    while ((stop < len(self.tokens)) and RE_PUNCTUATION.match(self.tokens[stop])):
        stop += 1
    return (start, stop)
