code: def format_params_diff(parameter_diff):
      
  
      params_output = '\n'.join([line for v in parameter_diff
                                 for line in v.changes()])
      return """--- Old Parameters
  +++ New Parameters
  ******************
  %s\n""" % params_output
docs: Handles the formatting of differences in parameters.
  
      Args:
          parameter_diff (list): A list of DictValues detailing the
              differences between two dicts returned by
              :func:`stacker.actions.diff.diff_dictionaries`
      Returns:
          string: A formatted string that represents a parameter diff