code: def parse_names_and_default(self):
          
          result = {}
          for title, text in self.formal_content.items():
  
              if not text:
                  result[title] = []
                  continue
  
              logger.debug('\n' + text)
  
              collect = []
              to_list = text.splitlines()
  
              # parse first line. Should NEVER failed.
              # this will ensure in `[default: xxx]`,
              # the `xxx`(e.g: `\t`, `,`) will not be changed by _format_line
              previous_line = to_list.pop(0)
              collect.append(self.parse_line_option_indent(previous_line))
  
              for line in to_list:
                  indent_match = self.indent_re.match(line)
                  this_indent = len(indent_match.groupdict()['indent'])
  
                  if this_indent >= collect[-1]['indent']:
                      # A multi line description
                      previous_line = line
                      continue
  
                  # new option line
                  # deal the default for previous option
                  collect[-1]['default'] = self.parse_default(previous_line)
                  # deal this option
                  collect.append(self.parse_line_option_indent(line))
                  logger.debug(collect[-1])
                  previous_line = line
              else:
                  collect[-1]['default'] = self.parse_default(previous_line)
  
              result[title] = [
                  (each['option'], each['default']) for each in collect]
  
          return result
docs: parse for `parse_content`
          {title: [('-a, --all=STH', 'default'), ...]}