I am generating a random numerical 6-10 digit password. I need some important reviews of yours.  Is it OK or are there some needed modifications?val AB = 0123456789669900val rnd = new Random()def randomNumericalString(): String = {    val len = rnd.nextInt(5) + 5    val sb = new StringBuilder(len)    for (i <- 0 to len)      sb.append(AB.charAt(rnd.nextInt(AB.length())))    return sb.toString  }
Random 6 to 10 digits number
scala;random