code: func NewHeightFromBytes(b []byte) (*Height, int) {
  	blockNum, n1 := util.DecodeOrderPreservingVarUint64(b)
  	txNum, n2 := util.DecodeOrderPreservingVarUint64(b[n1:])
  	return NewHeight(blockNum, txNum), n1 + n2
  }
docs: // NewHeightFromBytes constructs a new instance of Height from serialized bytes