前端消息提示两次后第一次提示关不掉

Question

(function () {
    window.Message = class Message {
        constructor(type, message, timerout) {
            this.dom = null;
            this.type = type;
            this.message = message;
            this.timerout = timerout;
        }
        showMessage() {
            let writediv = document.createElement("div");
            writediv.setAttribute("class", "wr")
            writediv.innerHTML = this.message;
            this.dom = writediv;
            switch (this.type) {
                case "success":
                    writediv.setAttribute("class", "wr1");
                    break;
                case "waring":
                    writediv.setAttribute("class", "wr2");
                    break;
                case "error":
                    writediv.setAttribute("class", "wr3");
                    break;
            }
            document.body.append(writediv);
            setTimeout(() => {
                this.hiddenMessage();
            }, this.timerout);
        }
        hiddenMessage() {
            document.body.removeChild(this.dom);
        }
    }
})()

报错内容：Uncaught DOMException: Failed to execute 'removeChild' on 'Node': The node to be removed is not a child of this node.

报错截图：