function inheritClass(Parent, child) {
    function Child() {
        var that = new (Parent.bind.apply(
            Parent,
            [].concat.apply([null], arguments)
        ))();

        return (
            child.constructor.apply(
                Object.setPrototypeOf(that, Child.prototype),
                arguments
            ) || that
        );
    }
    Object.assign(Child, child.static);
    Child.prototype = Object.create(Parent.prototype);
    Child.prototype.constructor = Child;
    Object.assign(Child.prototype, child.prototype);

    return Child;
}

function Parent(name) {
    this.name = name;
}

Parent.prototype.speak = function () {
    return "Hi, my name is " + this.name;
};

var Child = inheritClass(Parent, {
    constructor: function (name, age) {
        this.age = age;
    },
    prototype: {
        speak: function () {
            return [
                Parent.prototype.speak.call(this),
                "I'm " + this.age + " years old"
            ].join("\n");
        }
    }
});

var parent = new Parent("Donald"),
    child = new Child("Ivanka", 38);

console.assert(child instanceof Child, "inherited from Child");
console.assert(child instanceof Parent, "inherited from Parent");

console.assert(
    Parent.prototype.speak !== Child.prototype.speak,
    "Parent's prototype is safe"
);
console.assert(child.constructor === Child, "Child's constructor is correct");

console.assert(
    child.speak() === "Hi, my name is Ivanka\nI'm 38 years old",
    "override Prototype methods"
);