code: public static WxOutMsg fix(WxInMsg in, WxOutMsg out) {
          out.setFromUserName(in.getToUserName());
          out.setToUserName(in.getFromUserName());
          out.setCreateTime(System.currentTimeMillis() / 1000);
          return out;
      }
docs: 根据输入信息,修正发送信息的发送者和接受者