[Rise]

class Test{
    constructor() {
        this.req = new XMLHttpRequest();
        this.req.addEventListener("onreadystatechange", this, false);
        this.param = 5;
    }
    handleEvent(e) {
        console.log(this); // { req: XMLHttpRequest, param: 5 }
        console.log(this.param) // 5
    }
}