JSFiddle - React, Tailwind, and code Playground

JavaScript

YUI().use('base', function (Y) {

    ns = Y.namespace('lptest');
    ns.First = new Y.Base.create('first', Y.Base, [], {
        initializer: function (cfg) {
            console.log('first', cfg)
        }
    }, {
        ATTRS: {
            prop1: {
                value: 'test'
            }

        }
    });


    var test = new ns.First({
        prop1: 3
    });
            
    console.log(test.get('prop1'));

});