JSFiddle - React, Tailwind, and code Playground

JavaScript

function Base() {
    this.close = function() { alert('base close'); }
}

function Child() {
    
    var self = this;
    Base.call(this);
    
    this.close = (function() { 
        var baseClose = self.close;
        return function() {
            baseClose.call(self);
            alert('child close');
        };
    })();
}

var base = new Base(),
    child = new Child();

base.close();
child.close();