code: function () {
      var text = ''
      var regx = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
      for (var idx = 0; idx < 8; idx++) {
        text = text + regx.charAt(Math.floor(Math.random() * regx.length))
      }
      return text
    }
docs: Generate a unique string