code: func (r *Reader) Next() bool {
  	if r.err != nil {
  		return false
  	}
  	if r.c != nil {
  		io.Copy(ioutil.Discard, r.c.blockData)
  	}
  	var c Container
  	r.err = c.readFrom(r.r)
  	r.c = &c
  	return r.err == nil
  }
docs: // Next advances the Reader to the next CRAM container. It returns false
  // when the stream ends, either by reaching the end of the stream or
  // encountering an error.