ES6中函数调用自身需要注意的问题

function sum(n) {
    return sum(n - 1) + n;
}

this.rendering= this.rendering.bind(this);
rendering() {
    requestAnimationFrame(this.rendering);
    this.cube.rotation.x += 0.1;
    this.cube.rotation.y += 0.1;
    this.renderer.render(this.scene, this.camera);
}

rendering() {
    requestAnimationFrame(()=>this.rendering);
    this.cube.rotation.x += 0.1;
    this.cube.rotation.y += 0.1;
    this.renderer.render(this.scene, this.camera);
}