def update_headers(self,fields=None):
    '''update headers with a token & other fields
    '''
    do_reset = True
    if hasattr(self, 'headers'):
        if self.headers is not None:
            do_reset = False

    if do_reset is True:
        self._reset_headers()

    if fields is not None:
        for key,value in fields.items():
            self.headers[key] = value

    header_names = ",".join(list(self.headers.keys()))
    bot.debug("Headers found: %s" %header_names)
update headers with a token & other fields