'Write a tempory group after accepted control words end
But this is mostly useless in my opinion as there is no list of rejected cw
This may be a way to implement future old rtf processing for cw
Utility: open a group to just put brackets but why be so complicated?
Scheme: open brackets, write cw then go to body and back with cw after'

def __write_group(self):

    if self.__open_bracket:
        self.__write_obj.write('cb<nu<clos-brack<0003\n')
        self.__open_bracket = False
    inline_string = ''.join([('%s<nu<%s\n' % (k, v)) for (k, v) in self.__inline.iteritems() if (v != 'false')])
    if inline_string:
        self.__write_obj.write(('ob<nu<open-brack<0003\n%s' % inline_string))
        self.__open_bracket = True
    self.__temp_group = []
