code: function pack(buffs, extra) {
    var lengths = [],
        lenbytes = [],
        len = buffs.length,
        extra = extra || 0,
        sum = 0,
        offset = 0,
        mb,
        i
  
    for (i = 0; i < len; i++) {
      lengths.push(buffs[i].length)
      lenbytes.push(vencode(lengths[i]))
      sum += lengths[i] + lenbytes[i].length + extra
    }
  
    mb = new Buffer(sum)
    for (i = 0; i < len; i++) {
      for (var j = 0; j < lenbytes[i].length; j++) {
        mb.writeUInt8(lenbytes[i][j], offset + extra)
        offset = offset + 1 + extra
      }
      buffs[i].copy(mb, offset, 0, lengths[i])
      offset += lengths[i]
    }
    return mb
  }
docs: Combine an array of buffers into a single buffer encoded such that they can all be extracted again.
  @param  {Array[Buffer]} buffs An array of Buffers
  @param  {int} extra How many extra empty leading bytes to put in each buffer
  @return {Buffer}       A single buffer that is an encoded concatentation of buffs