UUID Generator (https://stackoverflow.com/a/8809472)

UUID_generator.js

function generateUUID () {
    let time = new Date().getTime();
    if (typeof performance !== 'undefined' && typeof performance.now === 'function'){
        time += performance.now();
    }
    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
        let random = (time + Math.random() * 16) % 16 | 0;
        time = Math.floor(time / 16);
        return (c === 'x' ? random : (random & 0x3 | 0x8)).toString(16);
    });
}