function getUuid(len){
    let timeStr = String(Date.now() % 100)
    const str = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
    for(let i=0;i<len - timeStr.length;i++){
        const idx = Math.floor(Math.random() * str.length) 
        timeStr += str[idx]
    }
    const arr = timeStr.split('')
    arr.sort(()=>Math.random()-.5)
    return arr.join('')
}

function uuid() {
  const randomPart = Math.random().toString(36).substring(2, 6) + Math.random().toString(36).substring(2, 6);
  const timestampPart = Date.now().toString(36);
  return randomPart + timestampPart;
}