// https://babeljs.io/docs/en/babel-plugin-proposal-private-methods // Test for `classPrivateProperties` and `classPrivateMethods` class Counter extends HTMLElement { #xValue = 0; #render() {} get #x() { return this.#xValue; } set #x(value) { this.#xValue = value; window.requestAnimationFrame(this.#render.bind(this)); } #clicked() { this.#x++; } }