How to test that method sussessfully using Junit?

public String create() {
    request.setAttribute(CommonConstants.PAGE_ID.toString(),
            ApplicationConstants.ADD_ATTRIBUTE_PAGE.toString());
    request.setAttribute(CommonConstants.SCREEN_ID.toString(),
            ApplicationConstants.ADD_ATTRIBUTE_PAGE.toString());
    return SUCCESS;
}

CommonConstants, ApplicationConstants are enum.
"request" is object of HttpServletRequest.
"request" is the object of HttpServletRequest.