JS Bin// source https://jsbin.com/zucekaworu
const obj = {
prop1: "prop 1 name"
}
// hasOwnProperty
Object.prototype.myHasOwnProperty = function(prop) {
const proto = this.constructor.prototype;
return prop in this && (!(prop in proto) || this[prop] !== proto[prop]);
};
console.log(obj.myHasOwnProperty("prop1"));