code: func (s *Stack) PeakHeader() (header []byte, err error) {
  	if s.depth == 0 {
  		return nil, nil
  	}
  	s.guard.Lock()
  	defer s.guard.Unlock()
  	s.lastAccess = time.Now()
  	file, err := s.getFile()
  	if err != nil {
  		return nil, err
  	}
  	header = make([]byte, s.currentBlock.HeaderSize)
  	// Read header
  	_, err = file.ReadAt(header, int64(s.currentBlock.HeaderPoint))
  	if err != nil {
  		return nil, err
  	}
  	return header, nil
  }
docs: // PeakHeader get only header part from tail segment from stack without remove