docs: protected JsonObjectBase buildFieldError(BindingResult bindingResult, ErrorCode errorCode) {
  
          Map<String, String> errors = new HashMap<String, String>();
          for (Object object : bindingResult.getAllErrors()) {
              if (object instanceof FieldError) {
                  FieldError fieldError = (FieldError) object;
                  String message = fieldError.getDefaultMessage();
                  errors.put(fieldError.getField(), message);
              }
          }
  
          if (errorCode == null) {
              return JsonObjectUtils.buildFieldError(errors, ErrorCode.FIELD_ERROR);
          }
          return JsonObjectUtils.buildFieldError(errors, errorCode);
      }