code: func (d *Dataset) GetProperty(key string) (string, error) {
  	out, err := zfs("get", "-H", key, d.Name)
  	if err != nil {
  		return "", err
  	}
  
  	return out[0][2], nil
  }
docs: // GetProperty returns the current value of a ZFS property from the
  // receiving dataset.
  // A full list of available ZFS properties may be found here:
  // https://www.freebsd.org/cgi/man.cgi?zfs(8).