code: public static <Request> Input create(Request requestBean) {
          if (requestBean == null)
              throw new IllegalArgumentException("request bean should not be null!");
          Class requestClass = requestBean.getClass();
          return create(requestClass);
      }
docs: generate an input object from the bean.
  
  @param requestBean the request bean
  @param <Request>   the request bean type
  @return a newly created input definition.