code: func (this MBR) Write(disk io.Writer) error {
  	_, err := disk.Write(this.bytes)
  	return err
  }
docs: /*
  Write MBR to disk
  Example:
  f, _ := os.OpenFile("/dev/sda", os.O_RDWR | os.O_SYNC, 0600)
  err := Mbr.Write(f)
  if err != nil ...
  f.Close()
  */