SOURCE

Function.prototype.a = () => {
  console.log(1)
}
Object.prototype.b = () => {
  console.log(2)
}
function A() {}      //属于A.__proto__ = Object.prototype   A.constructor == Function
                     //
const a = new A()    // a.__proto__ = A.prototype
A.b()    //
A.a()
a.a()
a.b()    //