get Usage section and set to `raw_content`, `formal_content` of no
        title and empty-line version

def parse_content(self, text):
        """get Usage section and set to `raw_content`, `formal_content` of no
        title and empty-line version"""
        match = re.search(
            self.usage_re_str.format(self.usage_name),
            text,
            flags=(re.DOTALL
                   if self.case_sensitive
                   else (re.DOTALL | re.IGNORECASE)))

        if match is None:
            return

        dic = match.groupdict()
        logger.debug(dic)
        self.raw_content = dic['raw']
        if dic['sep'] in ('\n', '\r\n'):
            self.formal_content = dic['section']
            return

        reallen = len(dic['name'])
        replace = ''.ljust(reallen)
        drop_name = match.expand('%s\\g<sep>\\g<section>' % replace)
        self.formal_content = self.drop_started_empty_lines(drop_name).rstrip()