var areIntlLocalesSupported = require('intl-locales-supported');

var localesMyAppSupports = [
    /* list locales here */
];

if (global.Intl) {
    // Determine if the built-in `Intl` has the locale data we need.
    if (!areIntlLocalesSupported(localesMyAppSupports)) {
        // `Intl` exists, but it doesn't have the data we need, so load the
        // polyfill and replace the constructors we need with the polyfill's.
        require('intl');
        Intl.NumberFormat   = IntlPolyfill.NumberFormat;
        Intl.DateTimeFormat = IntlPolyfill.DateTimeFormat;
    }
} else {
    // No `Intl`, so use and load the polyfill.
    global.Intl = require('intl');
}