export const uuidV4 = () => {
  let dt = new Date().getTime()
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
    const r = (dt + Math.random() * 16) % 16 | 0
    dt = Math.floor(dt / 16)
    return (c == 'x' ? r : (r & 0x3) | 0x8).toString(16)
  })
}