How to know whether an object is proxy?
function A(n){this.n=n;};
let a = new A(1);
let p = new Proxy(a,{});
console.log('p.constructor == Proxy; // ', p.constructor == Proxy);
console.log('p.constructor == A; // ', p.constructor == A);
console.log('Proxy.prototype: ', Proxy.prototype); // null
console.log('Object.getPrototypeOf(p) == Object.getPrototypeOf(a); // ',
Object.getPrototypeOf(p) == Object.getPrototypeOf(a));
console.log('\n');
