@Override
 protected CommandExecutionResult executeArg(List<String> arg) {
   final String code;
   final String display;
   if (arg.get(1) == null) {
     if (StringUtils.eventuallyRemoveStartingAndEndingDoubleQuote(arg.get(0)).length() == 0) {
       code = "##" + UniqueSequence.getValue();
       display = null;
     } else {
       code = StringUtils.eventuallyRemoveStartingAndEndingDoubleQuote(arg.get(0));
       display = code;
     }
   } else {
     display = StringUtils.eventuallyRemoveStartingAndEndingDoubleQuote(arg.get(0));
     code = arg.get(1);
   }
   final Group currentPackage = getSystem().getCurrentGroup();
   // if (getSystem().entityExist(code)) {
   // return CommandExecutionResult.error("Package cannot have the same
   // name as an existing class");
   // }
   final Group p =
       getSystem().getOrCreateGroup(code, display, null, GroupType.PACKAGE, currentPackage);
   p.setBold(true);
   final String color = arg.get(2);
   if (color != null) {
     p.setBackColor(HtmlColor.getColorIfValid(color));
   }
   return CommandExecutionResult.ok();
 }