code: protected void setAttachmentByExample(String example, Object att, String exp){
  		int p = getLastAcceptedState(example, 0);
  		if (p != -1){
  			this.attachments[p] = att;
  		}else{
  			// 说明精确匹配示范字符串有错误
  			throw new IllegalArgumentException("\"" + example + "\" can not match \"" + exp + "\"");
  		}
  	}
docs: Set attachment object for each state, by testing which state the example string can run into.<br>
  根据示范字符串，设置各状态所对应的附件对象。
  
  @param example	Example string.<br>示范字符串
  @param att		Attachment object.<br>附件对象
  @param exp		Regular expression which will only be used within the exception message.<br>
  正则表达式字符串（仅被用在抛出的异常消息中）