code: public Expiring<T> handleFormer() {
  		if (null == this.defaultExpireTime || null == this.defaultExpireUnit) {
  			throw new UnsupportedOperationException(
  					"There is no default expire info, call Expiring#withDefault(long, TimeUnit) first");
  		}
  		
  		this.handleExistEls = true;
  		return this;
  	}
docs: Will append the expire info to the delegate elements that already add with default expire time and unit
  , default is not append. Need call {@link Expiring#withDefault(long, TimeUnit)} first
  @see #unhandleFormer()
  @return