docs: def parse_content(self, text):
          """parse section to formal format
  
          raw_content: {title: section(with title)}. For `help` access.
  
          formal_content: {title: section} but the section has been dedented
          without title. For parse instance"""
          raw_content = self.raw_content
          raw_content.clear()
          formal_collect = {}
  
          with warnings.catch_warnings():
              warnings.simplefilter("ignore")
              try:
                  split = self.visible_empty_line_re.split(text)
              except ValueError:  # python >= 3.5
                  split = [text]
  
          option_split_re = self.option_split_re
          name = re.compile(re.escape(self.option_name), re.IGNORECASE)
          for text in filter(lambda x: x and x.strip(), split):
  
              # logger.warning('get options group:\n%r', text)
              with warnings.catch_warnings():
                  warnings.simplefilter("ignore")
                  try:
                      split_options = option_split_re.split(text)
                  except ValueError:  # python >= 3.5
                      continue
  
              split_options.pop(0)
  
              for title, section in zip(split_options[::2], split_options[1::2]):
                  prefix, end = name.split(title)
  
                  prefix = prefix.strip()
  
                  section = section.rstrip()
                  if end.endswith('\n'):
                      formal = section
                  else:
                      formal = ' ' * len(title) + section
  
                  formal_collect.setdefault(prefix, []).append(formal)
  
                  # logger.error((title, section))
                  if prefix in raw_content:
                      # TODO: better handling way?
                      if self.namedoptions:
                          log = logger.warning
                      else:
                          log = logger.debug
                      log('duplicated options section %s', prefix)
  
                      raw_content[prefix] += '\n%s%s' % (title, section)
                  else:
                      raw_content[prefix] = title + section
  
          if formal_collect:
              for each_title, values in formal_collect.items():
                  value = '\n'.join(map(textwrap.dedent, values))
                  formal_collect[each_title] = value
  
          self.formal_content = formal_collect