new.js

// I'm keeping .class and $selector separated for edge cases in which dom-content is dynamic and can't be cached.
const $multiSelect = $('.js-multiselect'),
    defaults = {
        buttonClass: 'btn btn-default',
        buttonWidth: '100%',
        nonSelectedText: '---',
        nSelectedText: ' selected',
        allSelectedText: 'All',
        includeSelectAllOption: false,
        numberDisplayed: 1,
        enableFiltering: false,
        enableCaseInsensitiveFiltering: false
    };