code: func (h *Height) Compare(h1 *Height) int {
  	res := 0
  	switch {
  	case h.BlockNum != h1.BlockNum:
  		res = int(h.BlockNum - h1.BlockNum)
  		break
  	case h.TxNum != h1.TxNum:
  		res = int(h.TxNum - h1.TxNum)
  		break
  	default:
  		return 0
  	}
  	if res > 0 {
  		return 1
  	}
  	return -1
  }
docs: // Compare return a -1, zero, or +1 based on whether this height is
  // less than, equals to, or greater than the specified height respectively.