logger.error("Failed to write an image file: {}", fileName, e);
            throwValidationError(messages -> messages.addErrorsFailedToWriteDesignImageFile(GLOBAL), this::asListHtml);
        }
        return redirect(getClass());
    }

    private boolean checkFileType(final String fileName, final String[] exts) {
        if (fileName == null) {
            return false;
        }