func (h *headerGNU) realSize() []byte    { return h[483:][:12] }

type headerSTAR [blockSize]byte

func (h *headerSTAR) v7() *headerV7      { return (*headerV7)(h) }
func (h *headerSTAR) magic() []byte      { return h[257:][:6] }
func (h *headerSTAR) version() []byte    { return h[263:][:2] }
func (h *headerSTAR) userName() []byte   { return h[265:][:32] }
func (h *headerSTAR) groupName() []byte  { return h[297:][:32] }