module.exports = (lastId = '', maxlength = 6) => {
  let allChar = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
  let resChar = ''
  for(let i = 0; i < maxlength; i++) {
    resChar += allChar.charAt(Math.floor(Math.random() * allChar.length))
  }
  return `${lastId}${resChar}`
}