code: def _set_comment(self, section, comment, key=None):
          
  
          if '\n' in comment:
              comment = '\n# '.join(comment.split('\n'))
          comment = '# ' + comment
  
          if key:
              self._comments[(section, key)] = comment
          else:
              self._comments[section] = comment
docs: Set a comment for section or key
  
          :param str section: Section to add comment to
          :param str comment: Comment to add
          :param str key: Key to add comment to