JSFiddle - React, Tailwind, and code Playground

JavaScript

(function($, undefined){
    $.FCallbacks = function(flags, fns) {
        var i = $.type(flags) === 'string' ? 1 : 0,
            callbacks = $.Callbacks(i ? flags : undefined);
        callbacks.add(Array.prototype.slice.call(arguments, i))
        return $.extend(callbacks.fire, callbacks, { fcallbacks: true });
    };
})(jQuery);

function fn1(p1, p2) { console.log('fn1 says:', this, p1, p2); }
function fn2(p1, p2) { console.log('fn2 says:', this, p1, p2); }
var callbacks = $.FCallbacks('once', fn1);
callbacks.add(fn2);
callbacks(2, 3);