code: function divide(buf, n) {
    /* eslint-disable no-bitwise */
    var i = 0, l, t, rem;
  
    t = buf[i];
    rem = t % n;
    buf[i] = Math.floor(t / n);
  
    for (i = 1, l = buf.length; i < l; i++) {
      t = rem * 256 + buf[i];
      rem = t % n;
      buf[i] = Math.floor(t / n);
    }
  
    return rem;
  }
docs: internal
  divide(buf, n) -> Number
  - buf(Buffer): divident
  - n(Number): divisor
  
  Performs integer division of buf by n (modifying buf in-place)
  and returns a reminder.
  
  `n` must be one digit (i.e. lower than 256)