docs: function pack(id, type, body) {
      var buf = new Buffer(body.length + 14);
      buf.writeInt32LE(body.length + 10, 0);
      buf.writeInt32LE(id, 4);
      buf.writeInt32LE(type, 8);
      body.copy(buf, 12);
      buf[buf.length-2] = 0;
      buf[buf.length-1] = 0;
      return buf;
  }