SOURCE

class A{
    b = 111;
    constructor(){
        this.a =1;
    }
}

A.use = function(plugin, ...args) {
    // console.log(plugin, ...args)
    console.log(this)
    plugin(this, args)
}

function install(V,x) {
    V.prototype.say = () => {console.log('aaaaa',x)}
}

A.use(install, 999, 888)
// install(A)
let a = new A()
a.say()

console.log(a.b)