anchor.diff:          true  -> set_default_value(Pat)
         end;
       Children ->
  -      set_children(Pat, [do_fix_list_arguments(C, FixThese) || C <- Children])
  +      set_children(Pat, [do_fix_repeating_arguments(C, FixThese) || C <- Children])
     end.
   
   -spec fix_either(pattern() | patterns()) -> pattern() | patterns().
  
positive.code:   Opts0                = parse_doc_options(Doc),
    {Pattern, Opts1}     = parse_pattern(formal_usage(Usage), Opts0),
    ParsedArgs           = parse_args(Args, Opts1),
    {FixedPattern, Opts} = fix_list_arguments(Pattern, Opts1),
    case match(FixedPattern, ParsedArgs) of
      {true, [], Collected} ->
        debug("\n"
  
negative.code:                     [arg(undefined, "1"), arg(undefined, "2")]))
    ].
  
  fix_repeating_arguments_test_() ->
    Fix = fun(Pat) ->
              {Fixed, _} = fix_repeating_arguments(Pat, []),
              Fixed
          end,
    [ ?_assertEqual(opt("-a"), Fix(opt("-a")))
  