text: let _uid = ''
  
  export function getUid() {
    if (_uid) {
      return _uid
    }
    if (!_uid) {
      const t = (new Date()).getUTCMilliseconds()
      _uid = '' + Math.round(2147483647 * Math.random()) * t % 1e10
    }
    return _uid
  }
  