code: func unparseScript(pops []parsedOpcode) ([]byte, error) {
  	script := make([]byte, 0, len(pops))
  	for _, pop := range pops {
  		b, err := pop.bytes()
  		if err != nil {
  			return nil, err
  		}
  		script = append(script, b...)
  	}
  	return script, nil
  }
docs: // unparseScript reversed the action of parseScript and returns the
  // parsedOpcodes as a list of bytes