Jquery正在模块中返回prevObject

'use strict';

var s,
    toggleNavigation = {

        settings: {
            button: $('.burger'),
            active: 'is-active'
        },

        init: function() {
            s = this.settings;
            this.bind();
        },

        bind: function() {
            s.button.on("click", function() {
                s.button.toggleClass(s.active);
            });

        }

    }

module.exports = toggleNavigation